fixed crash when an OSL shader cannot be found.
Added output file parameter for appleseed.cli
Added option to not save aovs. Formatting fixes.
Removed cli prefix for output frame options.
Merge pull request #603 from est77/est_cli_output_param

appleseed.cli output filename Frame param
fixed typo.
small code tweaks and cleanups.
fixed copyright notices displayed at runtime.
Merge branch 'master' of github.com:appleseedhq/appleseed
small code tweaks.