fix(service): ignore case when matching wildcards in available langua…

…ges map

By ignoring case in language map wildcards, there is no longer any need for redundant
entries covering every single combination for each language. I.e. 'en_*' will match 'En-UK',
'eN_UK' as well as 'EN_UK'.

Relates #1789

src/service/translate.js

@@ -175,7 +175,7 @@ function $translate($STORAGE_KEY, $windowProvider, $translateSanitizationProvide
             angular.lowercase(langKeyAlias) === angular.lowercase(preferred);
 
           if (langKeyAlias.slice(-1) === '*') {
-            hasWildcardKey = langKeyAlias.slice(0, -1) === preferred.slice(0, langKeyAlias.length - 1);
+            hasWildcardKey = angular.lowercase(langKeyAlias.slice(0, -1)) === angular.lowercase(preferred.slice(0, langKeyAlias.length - 1));
           }
           if (hasExactKey || hasWildcardKey) {
             alias = $languageKeyAliases[langKeyAlias];