fix WTreeView drag bug in combination with different themes
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'
Added missing repaint operations to WPolygonArea

According to http://redmine.webtoolkit.eu/issues/2330 it was not
possible to move a WPolygonArea around after creation. This is fixed now
Merge remote-tracking branch 'upstream/master'
Merge pull request #42 from Sulando/master

fix WTreeView drag bug in combination with different themes, added missing repaint operations in WPolygonArea