[Frontend] Apply flex layout to object header elements

open #250
open #260
vista#132
Major refactoring to markup and CSS to apply
flex layout strategy to object headers;
Flex necessary to fix 'overflow: hidden' setting
applied in open90 to object-browse-bar that
was preventing the view switcher menu from
appearing;
Browse, edit, mobile, frames in layouts, etc. all
visually checked in a first go round;
Mobile classes tweaked to fix left and right
margin problems resulting from open90 changes;
z-indexing of Inspector pane and splitters changed
to allow primary pane elements to overflow beneath
when primary pane width is severely constrained;

platform/commonUI/general/res/sass/controls/_controls.scss

@@ -214,7 +214,7 @@ label.checkbox.custom {
 
     .l-elem-wrapper {
         //@include test(#66f, 0.2);
-        @include justify-content(flex-start);
+        //@include justify-content(flex-start); // Commented out 11/6/15 open250
         mct-representation {
             // Holds the context-available item
             // Must have min-width to make flex work properly