Added i18n support

This adds a new provider on the `dialogs` module. This provider contains the collection of all strings used by default in the dialogs.

The `$dialogs` service now exposes a new function `translate`. By calling this function, the user can provide alternative translations to be used.

We integrate dialogs with this translation feature (using [i18n-node-angular](https://github.com/oliversalzburg/i18n-node-angular)) into our application as follows:

	var myModule = angular.module( "myModule", [
		"dialogs", "i18n"
	  ] )
	  .config( [
				 "$routeProvider", "$locationProvider", "$compileProvider",
				 function( $routeProvider, $locationProvider, $compileProvider ) {
					// stuff
				 }
			   ] )
	  .run( [
			  "i18n", "$dialogs",
			  function( i18n, $dialogs ) {
				i18n.ensureLocaleIsLoaded().then( function() {
				  // Retrieve original strings
				  var defaultStrings = $dialogs.translate();
				  var translated = {};
				  for( var translateable in defaultStrings ) {
					translated[ translateable ] = i18n.__( defaultStrings[ translateable ] );
				  }
				  var result = $dialogs.translate( translated );
				} );
			  }
			] );