* use locking on the OpenGL context (using two APIs, but since agl needs the cgl headers included, should be ok i think).
  refs #668
  refs #915

  I'm not sure its fixed, but this seems like a logical way to solve it. Freaking apple with their 5 OpenGL APIs.

Qt4 - Preferences. Add CONFIG_DIRECTORY_ITEM. Does not work, but does not harm. Why ? can a C++ guru explain me? thks!

before initializing LibVLC (refs #838)

More fixes to come

 * use Py_ssize_t as index type (cf http://www.python.org/dev/peps/pep-0353/)
 * fix audio_[gs]et_channel parameter/return value type

(Currently RTCP only Sender Reports are implemented.)

RTCP is auto-enabled for RTP/TS but this could be used by the RTP stream
output plugin to enable RTCP too (in that case, RTP encapsulation is done
in the stream output plugin, so the access output cannot know if it should
do RTCP or not).

Mac OS X gui: Make sure that misc.h is included as our NSScreen extension is used here. (Fix a warning about NSScreen's +screenWithDisplayID.)

    - this stuff is highly unfinished; needs much more work and testing
    - don't be surprised if you don't see anything when trying it out, this port is basically a big reminder for me to keep working on it ;-)
    - the access module is probably going to be ported from CoreFoundation-driven C to Cocoa-based Obj-C
    - everything will be 10.4-only, since EyeTV is only available this way as well
    - the plugin to put into EyeTV is compiled in UB-mode by default and incorporates Public Domain code provided by Elgato Systems GmbH

- Remove an useless variable