Reverting r78889 and r78865. Breaks changeslist on translatewiki (unpatrolled-flag...

Reverting r78889 and r78865. Breaks changeslist on translatewiki (unpatrolled-flag exclamation mark popping up on page histories and and diff-views where they shouldn't instead of an 'm' for minor)
-  = ChangesList::flag( 'minor' );
- The jquery effects plugin and collapsible implementation, also in those commits, are redundant now.
- If/when skins.commons is needed again, we can simply add that part back in.
- (r78891 is not reverted because the file it altered was deleted while r78865 was -merged)