Allow to run via python -m

In the pipeline, kpet is run via its installed entrypoint. If kpet is installed in a venv, this entrypoint script is non-portable, ie the venv cannot be moved as the python interpreter is hardcoded in it.

To make it possible to run kpet via 'python -m kpet' (which does not depend on the install location), move the main function to a __main__ module and adjust the entrypoint.

Signed-off-by: Michael Hofmann mhofmann@redhat.com