ENYO-3629: next parameter is no longer optional

* ENYO-3629: added lot of assertCb(next) and removed optional next() 
* ENYO-3629: re-indented for ENYO-3311, removed trailing white spaces
* ENYO-3629: added an assert
* ENYO-3629: EnyoEditor.saveAs removed next() invocation that was never used
* ENYO-3629: EnyoEditor.saveFile: assert callback parameter
* ENYO-3629: Ares._openDocument: assert callback parameter
* ENYO-3629: Ares._closeDocument doesn't need next arg
* ENYO-3629: merged _hideWaitPopup back into hideWaitPopup...
* ENYO-3629: removed dead code (leftover from ENYO-3082)
* ENYO-3629: reindented for ENYO-3311

Related JIRA: https://enyojs.atlassian.net/browse/ENYO-3629

Enyo-DCO-1.1-Signed-off-by: Dominique Dumont <dominique.dumont@hp.com>