I) Update to snapshot 20050607
II) Improve the bktr(4) device grab code [1] in sync with
multimedia/ffmpeg/files/grab_bsdbktr.c revision 1.9

1. Add support for DragonFly
2. Use proper castings
3. Test file descriptors before using them
4. Improve frame capture
5. Fix some errors
6. Clean up the signals on bktr(4) when closing the device

III) Re-enable video capture WITH_VIDEO_CAPTURE due to (II)

Submitted by: Steve O'Hara-Smith <steve@sohara.org> et al [1]