added gpodder package
moved wrapper declaration to preFixup
Use make install instead of setup.py directly.

Using setup.py results in the following error message:

    Missing file: share/applications/gpodder.desktop

    If you want to install, use "make install" instead of using
    setup.py directly. See the README file for more information.
Merge pull request #3327 from svenkeidel/gpodder

added gpodder package