re-enabled bsdfwrapper assertions
added support for light-emitting geometry in nested assemblies.
removed newlines from messages emitted by the command line parser.
reimplemented foundation::Quaternion::extract_axis_angle() to properly handle null axes.
Fixed some bugs in dict to dict conversions
Merge pull request #285 from est77/py_dict2dict_fixes

Fixed some bugs in dict to dict conversions
Merge remote-tracking branch 'upstream/master' into OSL
Added transparent and emission related things