* examples/properties.py:
    * gobject/Makefile.am:
    * gobject/__init__.py:
    * gobject/constants.py.in:
    * gobject/generate-constants.c: (main):
    * gobject/propertyhelper.py:
    * tests/Makefile.am:
    * tests/test_enum.py:
    * tests/test_interface.py:
    * tests/test_properties.py:

    Add a property helper, fixes #338098

svn path=/trunk/; revision=662