Add MiqWidget importing/exporting

Related to Bugzilla 1115106
https://bugzilla.redhat.com/show_bug.cgi?id=1115106

@gmcculloug @dclarizio @h-kataria Please Review.

Also note that the styling for the slick grid stuff is off, but I figured that could be fixed after this is in.
You're correct. Right now it is validating uniqueness by name, with a scope on the userid. This would simply be adding to that scope, since we want to be able to create separate MiqSchedules with the same name, but different towhat values, without worrying about the userid.