- add support for checkbox edit type and edit forms for vector layers
- selection of ui file in vector layer properties (general tab)
- the forms are opened when a feature is added or via identify.
The widgets on the ui have to be named like the attribute they are supposed
to edit or show. If the vector layer is not in editing mode, the widgets
will be disabled
git-svn-id: http://svn.osgeo.org/qgis/trunk@12077 c8812cc2-4d05-0410-92ff-de0c093fc19c