Changed order of header inclusion to work around a Pyton/PyQt bug.
Removed Plotviewer
Enforced compatibilty with python 2.4


git-svn-id: https://dng.biozentrum.unibas.ch/svn/openstructure/trunk@2704 5a81b35b-ba03-0410-adc8-b2c5c5119f08