ENYO-3033: Disable all action buttons of the designer when reload is in progress

Related JIRA: https://enyojs.atlassian.net/browse/ENYO-3033

The "reload" button is now disabled when the reload action is engaged and when "Delete/Undo/Redo" action are performed too.
All this buttons are available again when the rendering is finished.
"Delete/Undo/Redo" buttons are disabled too when a "reload" action is performed.

Enyo-DCO-1.1-Signed-off-by: Vincent HERILIER vincent.herilier@hp.com