Remove trailing whitespaces
Introduce __version__

Since the last release version was 0.5, tag the development version 0.5.99,
which will eventually end up in a 0.6 release.
Merge cli tool from mwalle/pyvxi11
setup.py: import version from version.py

Instead of duplicating the version, import it from the version.py file.
Ignore generated MANIFEST file in scm