morebits: make use of new wgIsRedirect variable

This approach works on edit/history pages, so is better than dumbly looking for the redirectText CSS class.
We still can't do better for soft redirects, though, since MW has no built-in support for them.
fluff: automatically accept rollbacks when carried out by a reviewer or sysop

When you undo a single edit via index.php, the undo is automatically
detected as returning the page to a stable revision, and is therefore
automatically accepted. But this is not true of the API.
Per request on WT:TW, and pending the resolution of MediaWiki bug 54812.
Merge branch 'master' of https://github.com/azatoth/twinkle.git