This fixes a regression brought by 7f485998

On skins2(tested on Linux), open and close the preferences dialog leads to a
crash, because the whole qt4 thread terminates unexpectedly.

This is due to setQuitOnLastWindowClosed set to true. As a dialog provider,
qt4 doesn't run any windows, and therefore just closing the preferences
 dialog box (via accept() or reject()) signals the qt4 thread to quit.

8554 is the IANA-registered RTSP alternative port

- setContentMargin is the same on all platforms
- color fixes on Linux

For users who'll want to revert to the old one for whatever reason

 - Gtk+ player
 - wx   player
 - Qt   player
 - DVD ripper using Gtk

The new version, merged into the RTP stream output, is supposed to be
better than the old one, except for two dropped features:

 - non-standard RAW/RAW/UDP and MP2T/H2221/UDP RTSP Transports, and
   x-playNow RTSP header: the only vague specification of this that I
   could find is this 10-year-old draft:
   http://www-rn.informatik.uni-bremen.de/ietf/mmusic/47/id/draft-sheedy-mmusic-rtsp-ext-00.txt
   They provide support for broken Amino STBs.

 - client number limiting: not sure how pertinent that is and if it
   would be the right way to implement/port it

If you think it's a problem to drop these features, speak now.
Ultimately the goal is to get rid of the old code (after the next major
release?)

Closes #568

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

They are only used by the thread and can be freed before the module closes.

If search.h is present but not tdestroy: implement it based on others t* functions
If search.h and tdestroy are not present: implement every t* functions.

Close must also be serialized (one single global lock/wait).

function call didn't match function prototype.

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

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