Autoreload and multi-source language loading (#117)

Partially addresses #83 and provides support for autoreloading of languages on the file system and when using rust-embed in debug builds.
Also provides support for overriding translations using multiple sources, useful for software that will be customized by the end user (such as avalanche-report) , or perhaps for an eventual implementation of in-place translation editing for #83

.gitignore

@@ -1,4 +1,5 @@
 /target
 **/*.rs.bk
 .vscode
-/i18n/pot
+/i18n/pot
+.neoconf.json