Changed from DOS to Unix format.
Fixed 'decimate' variable reference.
Fixed default histogram path.
Improved ffmpeg error reporting.
Remove end-sync orange frames.
Fixed is_orange_frame shell quoting.
Reduced is_orange_frame vertical crop.

The new height (was 50%, now 33%) crops out any bottom-of-page popups
(e.g. "$URL wants to use your device's location") that'd otherwise
muddy the (optional) end-of-test visual sync.
Fixed decimate args to support Unix.
Added unit test.