updated FindOPENSTRUCTURE script

the script now allows to specify components, say mol.
OPENSTRUCTURE_LIBRARIES will then only contain libraries of
modules specified.

git-svn-id: https://dng.biozentrum.unibas.ch/svn/openstructure/trunk@2139 5a81b35b-ba03-0410-adc8-b2c5c5119f08