open #468
Remove ng-class statements in favor of upstream .s-status-editing;
Restructure CSS accordingly;
NOTE: because edit.html has NOT been changed,
changes here will cause old edit mode to no longer display properly.
Don't integrate this CSS with old edit mode!
WTD-951
layout.html:
Added classes to and removed inline styles from drag handles,
Removed edge handles, leaving corner handles in NW, SW and SE only;
Added hover classes to display corner handles while editing;
Modified z-indexing to allow view switcher to be accessed while editing;
