Implement end exdenting

[Boldewyn]

Currently we only exdent at the start. End indenting and indenting both sides should be there, too.

Seems not too problematic, when I tested it in Firebug. We have to figure out a useful API though.

[mrcasual]

Thanks for the plugin. Any desire to implement pull quotes on both sides?

[Boldewyn]

Theoretically, yes. Unfortunately Codepoints.net completely consumes my little spare time at the moment, so it will last some time. Pull requests are, however, always welcome ;-)