Scripts for replaying various data clips and recording movies.

To record movies I used the xvidcap program in the mode where it saves
individual image files for each frame, then converted these to an
mpeg1 using ffmpeg.  The advantage of this approach is that the
compression need not run in real time at the same time as the program,
and in fact the tracker itself need not run in real-time which is
still a problem due to the disk activity from saving uncompressed
images.  If we set sleep_for in video.cfg so that we run at 1/5 real
time, then we can tell xvidcap to save at 2 fps, then tell ffmpeg that
these frames are 10fps video, and you get the correct 10fps final
frame rate.

gd_points*
gd_replay*
gd_replay.cfg
    These relate to usage of datmo with the XVU builtin 3D scanner,
    which did not work very well.

slice_gd*
    Generate a time slice from an XUV 4-scanner dataset
    usage: slice_gd source-dir start-time end-time out-dir

encode*
    Encode video from image files captured by xvidcap using ffmpeg.

vid*
video.cfg
    vid script sets env vars and runs datmomod with video.cfg to
    replay canned data to generate a video clip, see above.

xuv2demo*
xuv2demo.cfg
xuv4demo*
xuv4demo.cfg
    Scripts & config files for replaying datasets in 2 and 4 sick
    configurations.
