fix(fallbackLanguage): Fix fallback languages loading and applying
chore(fallbackLanguage): Improve coding style

Change typeof to angular.isString() and remove whitespaces
chore(fallbackLanguage): Change principle of determination to return string or array

Change a principle of determination what to return: string or array. A new principle is
based on what the user passed to the module.
Merge pull request #251 from DWand/fix-fallback-language-loading

fix(fallbackLanguage): Fix fallback languages loading and applying