CMS-1774 Convert mixin_get to use value objects

Model classes used by both ContentType and Mixin
CMS-1774 Convert mixin_get to use value objects

Fixes to frontend remote model
CMS-1774 Convert mixin_get to use value objects
CMS-1773 Convert mixin_list to use value objects
CMS-1776 Convert mixin_create (mixin_createOrUpdate) to use value objects
CMS-1777 Convert mixin_update (mixin_createOrUpdate) to use value objects
CMS-1775 Convert mixin_delete to use value objects
revert ts fixes

revert ts fixes
Merge pull request #314 from enonic/CMS-1774

CMS-1773, CMS-1774, CMS-1774, CMS-1776, CMS-1777