Add a format class for reading video files

Opening videos via the open transform will result in all frames of a video
being loaded into memory, and stored as matrices of a single template.
Modify defaultFormat to try to read a file as a video if it can't be read as an
image (since video files can also have various file extensions).

Signed-off-by: caotto <ottochar@gmail.com>
Add a class for treating videos as galleries

Add a gallery class for videos, treating each frame as a separate template in a
templatelist. Currently only uses the .avi file extension, other formats can be
read via something like "Open!other_operations," and I'm not aware of a
pressing reason to support output to other video containers

Signed-off-by: caotto <ottochar@gmail.com>
Abstract fourcc selection a little

Use 'x264' by default, users can specify which code to use by using
-fourcc 'code'
on the command line. On windows, a code of -1 will bring up the vfw codec
selection dialog.

Signed-off-by: caotto <ottochar@gmail.com>
Merge pull request #11 from biometrics/video_thing

some basic support for video processing