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.
Time.current gives you the time in UTC, whereas Time.now gives it to you in whatever timezone you have set. It's helped with Timecop and fixing other spec time related issues in the past.