Add "Scale (fit)" background image mode

The current "Scale" mode crops out part of the image if the scaled
image is larger than the terminal in any direction. This is useful for
most cases, such as wallpapers repurposed as terminal backgrounds.
However, this may be surprising to users coming from xfce4-terminal,
where the equivalent "Scaled" mode tries to fit the background within
the terminal in both dimensions. This new "Scale (fit)" mode is meant
to emulate this behaviour.

data/gsettings/com.gexperts.Tilix.gschema.xml

@@ -37,9 +37,10 @@
   <!-- Background Image Options -->
   <enum id='com.gexperts.Tilix.Background.Image.Mode'>
     <value nick='scale' value='0'/>
-    <value nick='tile' value='1'/>
-    <value nick='center' value='2'/>
-    <value nick='stretch' value='3'/>
+    <value nick='scale-fit' value='1'/>
+    <value nick='tile' value='2'/>
+    <value nick='center' value='3'/>
+    <value nick='stretch' value='4'/>
   </enum>
 
   <!-- Background Image Scaling Options, note these

po/ak.po

@@ -6,7 +6,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: tilix\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2021-02-10 20:32+0100\n"
+"POT-Creation-Date: 2021-05-01 17:05-0500\n"
 "PO-Revision-Date: 2017-04-01 20:36+0000\n"
 "Last-Translator: Lawrence Aberba <[email protected]>\n"
 "Language-Team: Akan <https://hosted.weblate.org/projects/tilix/translations/"
@@ -94,126 +94,126 @@ msgstr ""
 msgid "Tilix has been tested with GNOME and with Unity."
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:52
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:59
 msgid ""
 "Tilix is looking for maintainers! At the moment, only very minimal "
 "maintenance is done, no new features will be implemented and pull-requests "
 "may be reviewed very slowly."
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:53
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:60
 msgid "If you are interested in helping Tilix, please chime in!"
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:54
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:61
 msgid "This release adds the following features:"
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:56
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:63
 msgid "Actually install Yaru color scheme"
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:57
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:64
 msgid "Give every tab the ${title}"
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:58
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:65
 msgid "Add option to strip trailing whitespace on paste"
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:60
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:89
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:99
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:67
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:96
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:106
 msgid "This release fixes the following bugs:"
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:62
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:69
 msgid "Fix saving of already saved session"
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:63
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:70
 msgid "Add shortcut to \"Unselect all\""
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:64
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:71
 msgid "Many Meson buildsystem fixes"
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:65
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:72
 msgid "Avoid missing the previous command exit code when encoding URLs"
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:66
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:73
 msgid "Resolve some D deprecation messages"
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:67
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:74
 msgid "Mention powerline/fonts in README"
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:68
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:75
 msgid "Avoid calling `values()` on a shared object"
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:69
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:76
 msgid "Update metainfo data"
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:70
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:77
 msgid "Drop compat code for older D frontend versions"
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:71
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:78
 msgid "Bump minimum VTE version to 0.46"
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:72
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:79
 msgid "Remove deprecated Autotools support"
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:73
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:80
 msgid "Add release notes, NEWS file, automatic metainfo update"
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:74
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:81
 msgid "Update to GtkD 3.9.0"
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:76
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:83
 msgid "This release updates translations."
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:81
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:88
 msgid "This release fixes the following bug:"
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:83
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:90
 msgid ""
 "Fixes a problem with the session sidebar getting out of sync after having "
 "deleted a session. See issues #1680, #1637 and #1699."
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:91
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:98
 msgid "Remove app menu for gnome 3.32"
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:92
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:99
 msgid "Update icon"
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:93
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:100
 msgid "Minor fixes"
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:101
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:108
 msgid "Small release to update localizations"
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:102
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:109
 msgid "Update to GtkD 3.8.5 to fix library name in GtkD."
 msgstr ""
 
-#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:108
+#: data/metainfo/com.gexperts.Tilix.appdata.xml.rel.in:115
 msgid "Some new features and bug fixes."
 msgstr ""
 
@@ -1124,11 +1124,11 @@ msgstr ""
 msgid "Quake Mode Not Supported"
 msgstr ""
 
-#: source/gx/tilix/appwindow.d:2181
+#: source/gx/tilix/appwindow.d:2184
 msgid "New output displayed"
 msgstr ""
 
-#: source/gx/tilix/appwindow.d:2189
+#: source/gx/tilix/appwindow.d:2192
 msgid "Close session"
 msgstr ""
 
@@ -1849,6 +1849,10 @@ msgstr ""
 msgid "Scale"
 msgstr ""
 
+#: source/gx/tilix/prefeditor/prefdialog.d:1202
+msgid "Scale (fit)"
+msgstr ""
+
 #: source/gx/tilix/prefeditor/prefdialog.d:1202
 msgid "Stretch"
 msgstr ""
@@ -2520,43 +2524,43 @@ msgstr ""
 msgid "Help"
 msgstr ""
 
-#: source/gx/tilix/preferences.d:252
+#: source/gx/tilix/preferences.d:253
 msgid "UpdateState"
 msgstr ""
 
-#: source/gx/tilix/preferences.d:253
+#: source/gx/tilix/preferences.d:254
 msgid "ExecuteCommand"
 msgstr ""
 
-#: source/gx/tilix/preferences.d:254
+#: source/gx/tilix/preferences.d:255
 msgid "SendNotification"
 msgstr ""
 
-#: source/gx/tilix/preferences.d:255
+#: source/gx/tilix/preferences.d:256
 msgid "UpdateTitle"
 msgstr ""
 
-#: source/gx/tilix/preferences.d:256
+#: source/gx/tilix/preferences.d:257
 msgid "PlayBell"
 msgstr ""
 
-#: source/gx/tilix/preferences.d:257
+#: source/gx/tilix/preferences.d:258
 msgid "SendText"
 msgstr ""
 
-#: source/gx/tilix/preferences.d:258
+#: source/gx/tilix/preferences.d:259
 msgid "InsertPassword"
 msgstr ""
 
-#: source/gx/tilix/preferences.d:259
+#: source/gx/tilix/preferences.d:260
 msgid "UpdateBadge"
 msgstr ""
 
-#: source/gx/tilix/preferences.d:260
+#: source/gx/tilix/preferences.d:261
 msgid "RunProcess"
 msgstr ""
 
-#: source/gx/tilix/preferences.d:370
+#: source/gx/tilix/preferences.d:371
 #, c-format
 msgid "%s (Copy)"
 msgstr ""