Bug#729289: transition: openscenegraph

["Rebecca N. Palmer" <r.palmer@bham.ac.uk>]

openscenegraph is now in testing, flightgear and fgrun successfully 
built everywhere; should this bug now be closed?

Upstream talk of openscenegraph 3.2.1 has died down again, but uploading 
the fixed ossim would still be a good idea.