[Frontend] Further cleanups to form elements

#700
#689
#740
Removed _selects.scss and moved classes
into _controls.scss;
Reorg'd _controls;
Moved classes into _elems.scss;
Added and fixed cssclass defs in multiple
bundle.js files to allow better field widths
in overlay dialogs;
Fixed overlay custom scrollbar colors;
Fixed alignment of required glyphs in forms;

platform/features/pages/bundle.js

@@ -49,7 +49,8 @@ define([
                             "name": "URL",
                             "control": "textfield",
                             "pattern": "^(ftp|https?)\\:\\/\\/\\w+(\\.\\w+)*(\\:\\d+)?(\\/\\S*)*$",
-                            "required": true
+                            "required": true,
+                            "cssclass": "l-input-lg"
                         }
                     ]
                 }