configure.ac: fix linking the OSX UI module if the AVFoundation framework isn't present (read: OSX 10.6)

This module lets you capture video devices with the AVFoundation framework on Mac OS X.
It is an upgrade of the qtcapture module. Currently no GUI integration yet.
Only available via command line

Usage: avcapture://
Signed-off-by: Felix Paul Kühne <fkuehne@videolan.org>

Assuming stereo is fairly safe and still better than not decoding anything.
This is what gstreamer does, and mplayer might do the same thing.

Note that updated meta are still marked with access_t.info.i_update,
which remains undefined in case of threaded stream filter. Luckily,
unlike pf_control() re-entrancy, unprotected access to info.i_update
cannot crash on any practical system.

This was only used for INPUT_UPDATE_SIZE.

(vlc_open() takes care of that)

Signed-off-by: Felix Paul Kühne <fkuehne@videolan.org>

Do not leak mutex/conditional or fifo in transcode_video_new() its
error path when p_sys->i_thread > 1.

Do not leak mutex in sout_NewInstance() on error.

This reverts commit f3e0178e.

libtool always adds -nostdlib which renders these options useless

http://cl.ly/image/1K3l2C0v3T2V

Mac codes are only 0 to 0x3ff and 0x7fff.

Also add missing STREAM_CAN_FASTSEEK to HTTP live.

Turning off the cache makes no sense here, especially right after
enabling reading ahead (which intrisically means caching).