Attached patch adds input support for 16:9 DV video in QuickTime.

I found some old files produced by Adobe Premiere and Radius SoftDV which
were affected by this: 4:3 files were marked as type 'dvc ' which already
worked; 16:9 files as 'dvl ' which was missing. PAL uses 'p' in place of
the ' ' space character of NTSC in both versions, but I have no PAL sample
files.

Confirmed to work on real NTSC files; PAL not tested.

-- brion