ENYO-2978: Designer undo/redo improvements (WAIT for https://github.com/enyojs/ares-project/pull/531 to be merged)

Related JIRA: https://enyojs.atlassian.net/browse/ENYO-2778

Limitations of go/return between Phobos and Deimos
(De)Activation of delete/undo/redo buttons of designer during undo/redo updates

DO NOT MERGE until https://github.com/enyojs/ares-project/pull/531 is merged

Enyo-DCO-1.1-Signed-off-by: Vincent HERILIER vincent.herilier@hp.com