Fix unitialized pointer usages (possibly exploitable).

There is no functional changes.

Conflicts:

	NEWS

Fortunately, var_DelCallback does the job properly already.

libvlc kills the interfaces when it dies anyway.

It merely wrappeded the SAP object.

(cherry picked from commit 77cc89e3d9349f3d5a2de947f9be478dd28436dd)
(cherry picked from commit 6d4830b864af38d7126aee103a6bcfe76bc80e89)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

when --enable-v4l2 was passed to configure, alsa was searched and linked
against if found (only do that when alsa wasn't disabled)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

when --enable-freetype was passed to configure, fontconfig was searched
and linked against if found (provide --enable-fontconfig which is
default)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

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

macosx: added an option to the crash reporter to disable the submission of the default email address

Now that we have a one instance mode with DBus under linux, also make
it possible to use the "one-instance-when-started-from-file" and
"started-from-file" options.
Consider using --started-from-file in the file association scripts,
like what we do in the win32 NSIS script, so that all files opened
through the GUI are enqueued/played in the same instance.

Saves a few kB and prevents some, ehm, corruption.