Now, this should work safely, although it requires heavy polling.

This API is completely idiotic. By design, it requires (very active)
polling to work. Also, it is almost impossible to make it thread-safe.
Anyway, through violating a few constant pointers, we can fix half of
that. However, message item reference counting remains broken.

It was not thread-safe, and only used by ncurses (fixed earlier).

Changing the verbosity at that point is not thread-safe (and trying to
restore the value at ext is somwehat logically flawed). Luckily all the
standard <stdio.h> functions are thread-safe.

Signed-off-by: Rémi Denis-Courmont <rdenis@simphalempin.com>

Remove this define once the functionality is implemented on MacOS X and Win32.

Our outputs want to create a window as a child of the drawable. This is
never going to work with a pixmap.

This can happen when a rtsp client teardown : RtspCallback is called.
But at the same time, if the media is deleted, (MediaDel), RtspClientDel can be called twice on the same p_media/p_rtsp
Signed-off-by: Rémi Denis-Courmont <rdenis@simphalempin.com>

(and remove an unused argument).