Add eliding options to QLabel

Requested many times everywhere, and I needed it too just now: eliding in QLabel. There already is a broader suggestion to add eliding to several things:
http://bugreports.qt.nokia.com/browse/QTBUG-13445

Some examples of requests online:
http://www.archivum.info/qt-interest@trolltech.com/2010-01/00324/Re-%28Qt-interest%29-setElideMode-feature-on-QLabel.html
http://www.libqxt.org has done it in their library
http://www.qtcentre.org/threads/30525-QLabel-text-and-ElideMode-%28...%29
http://www.mentby.com/santhosh-y/setelidemode-feature-on-qlabel.html
http://www.cyblogic.com/en/blog/posts/10-showing-elided-text-in-a-qlabel
etc etc

Instead of everyone doing this themselves, please do this in QLabel so we don't all have to reinvent the wheel every time.