Fixed media_gallery descriptions.  #2192

Bug in os_files was breaking the form element that took media_description.  I removed it.

While the bug was active, several descriptions were given an incorrect format.  Both the description and format were set to the first character of the user's description text.  Wrote an update hook to correct this.
Merge branch 'SCHOLAR-3.x' into 2192-media_gallery_description

Conflicts:
	modules/os_features/os_image_gallery/os_image_gallery.install
Merge pull request #2215 from openscholar/2192-media_gallery_description

Fixed media_gallery descriptions.  #2192