[1/6] qedit: Add test framework and test for IMediaDet_put_Filename.

[Dan Kegel]

I think you can't depend on files existing in the source
directory; you have to create them yourself
(e.g. from a hex array in your source).
Otherwise the unified winetest app that we
use for semiautomated remote windows testing
by users won't work.

But if, say, WINETEST_INTERACTIVE is set, you
can still use test.avi in the local directory instead
of creating one.