Added configureIfNeeded method so there is no necessity to call confi…

…gure() if you want to configure it for main bundle

Swifternalization/Swifternalization.swift

@@ -35,6 +35,12 @@ final public class Swifternalization {
     */
     private var translations = [Translation]()
 
+    /**
+     Determine whether Swifternalization is configured.
+     It should be considered configured after `load(bundle:)` method is called.
+     */
+    private var configured = false
+
     // MARK: Public Methods
 
     /**
@@ -46,6 +52,16 @@ final public class Swifternalization {
         sharedInstance.load(bundle)
     }
 
+    /**
+     Configures Swifternalization if you didn't do that before calling
+     `localizedString...` methods.
+     */
+    private class func configureIfNeeded(bundle: NSBundle = NSBundle.mainBundle()) {
+        if sharedInstance.configured == false {
+            configure(bundle)
+        }
+    }
+
     /**
     Get localized value for a key.
 
@@ -83,6 +99,9 @@ final public class Swifternalization {
         specified or `key` if `defaultValue` is not specified.
     */
     public class func localizedString(key: String, stringValue: String, fittingWidth: Int? = nil, defaultValue: String? = nil, comment: String? = nil) -> String {
+
+        configureIfNeeded()
+
         /**
         Filter translations and get only these that match passed `key`.
         In ideal case when all is correctly filled by a developer it should be 
@@ -165,6 +184,7 @@ final public class Swifternalization {
 
         // Store processed translations in `translations` variable for future use.
         translations = LoadedTranslationsProcessor.processTranslations(baseTranslations, preferedLanguageTranslations: languageTranslations, sharedExpressions: expressions)
+        configured = true
     }
 
     /**