Add editorconfig, resolve differences

This includes newlines, tabs, among other things.

test-utils/xhrMock.js

@@ -10,7 +10,7 @@ module.exports = function() {
 	var serverErrorHandler = function() {
 		return {status: 500, responseText: "server error, most likely the URL was not defined"}
 	}
-	
+
 	var $window = {
 		XMLHttpRequest: function XMLHttpRequest() {
 			var args = {}
@@ -74,4 +74,4 @@ module.exports = function() {
 		},
 	}
 	return $window
-}
+}