qtcapture: New access_demux module (QTKit based) to capture video from your iSight Camera on Mac OS X.

Usage: 'vlc qtcapture://'.

This is a 2 hours hacked module. We don't grab sound yet, and there are a lot of FIXME.

Note: For some reason QTKit needs a the main thread to be a cocoa thread. Don't expect it to run with -I dummy for instance.

(that's one of the isight's chromas)

O_APPEND puts the file pointer to the end after _each_ write.
We want to put it at the end (only) after open.
Also allow reading/seeking stdout, as it could be a redirected file
(of course, it won't work if it's a terminal)

Still not working though

Thank you big time for committing stuff against people's review.

Should fix strlcpy() issues on Linux, but Win32 is surely still totally
broken by d754b405

Mark description & shortnames as translatable with N_
(Thanks for testing the build before committing, I think the source code
had the same review)

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

Please review whether this patch is correct as it adds internal functions using VLC_EXPORT.

Also fix an overflow in strndup().

I should not have put internal stuff into the header files anyway