Audio and video should use workbench instead of tempfiles

[Christopher Allan Webber]

The audio and video media types both write to temporary files instead of using the workbench... the workbench was designed for this though as a place to put files during processing that get removed when things are done.

The NamedTemporaryFile bits should be changed over to use the workbench unless there's good reason not to, and the end of these files' processing routines should call:

workbench.destroy_self()

[Christopher Allan Webber]

cc'ing joar

[spaetz]

I propose this fix by creating the tempfiles simply in the workbench directory. This will always work as the workbench is on the local filesystem.

at my repo: ​git://gitorious.org/~spaetz/mediagoblin/spaetz-mediagoblin.git.
It simply adds the (dir=workbench.dir) argument to the creation of all Tempfiles which seems clean enough.

This patch is part of the larger #419 issue (don't fail on large files). By using tempfiles (which might be on a smallish tmpfs) we would fail processing the stuff.

[Christopher Allan Webber]

Looks great... merged!

Also the workbench wasn't being killed on video processing also. Closing.

Thanks for your work on this!