Revert "Merge branch 'master' into ansel-ajax"

This reverts commit c50a6d2996a29b52df8eb304d86efd05d95c107f, reversing
changes made to 6b9aec9f83523dcde5a32305873bb8c31d626636.
Add a more general callback method.
todo
Not needed, and causes issues in certain cases.
Implement uploading in Ajax view.
Move uploader outside of main content area so menu can be hidden.
Ensure we don't return an empty json array.
Don't query for images if we know we don't have galleries.
Filter out special key images by default.
Groups -> All.

Might still implement the "Groups" view, but for now, change this
to an "All" view.
Implement the "All" filter/view.