[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;

example/generator/bundle.js

@@ -126,7 +126,7 @@ define([
                         {
                             "name": "Period",
                             "control": "textfield",
-                            "cssclass": "l-small l-numeric",
+                            "cssclass": "l-input-sm l-numeric",
                             "key": "period",
                             "required": true,
                             "property": [