There is still a lot of fixes to be backported here.

(before getopt_long gets the chance to reorder them)

Should be probably called backport [17739] but it's different
since libvlc went through significant changes in trunk.

closes #830

* Initialize all the fields in the sdp_t of out sap parser. Fixes a FreeSDP crash i was sometimes seeing on OS X.

  [17556] was supposed to contain this already, but i guess i made a mistake

- added custom events processing on main thread for plugin fullscreen window, this is similar to Cocoa [performSelectorOnMainThread]
- ShowWindow/HideWindow for plugin fullscreen window are now run on main thread as they are not thread safe and may cause crashes

#define PROTECTION_LEVEL_UNRESTRICTED  10  /* For peer-to-peer apps */
#define PROTECTION_LEVEL_DEFAULT       20  /* Default level         */
#define PROTECTION_LEVEL_RESTRICTED    30  /* For Intranet apps     */

closes #827

* Improve avformat demux SET_POSITION.
* Add WavPack ID for ffmpeg demux
* Add Speex ID for avi files

* check whether p_item->input.psz_name exists, because stringWith*String crashes on non-existant strings

* backport [17543] : Fix mpeg2 PTS/DTS for field pictures