rewrote stereo frustum logic, much improved stereo effect over wide...

rewrote stereo frustum logic, much improved stereo effect over wide z-translation settings, completely zplane independent
mouse z-translation scaled by current z-trans value
minor tweaks to verbosity settings
added missing shader
modified cmake to set rpath for install targets


git-svn-id: https://dng.biozentrum.unibas.ch/svn/openstructure/branches/new_gfx@2254 5a81b35b-ba03-0410-adc8-b2c5c5119f08