macosx: work-around CoreAnimation limitations on 10.6, which prevented the correct display of some ui elements

macosx: show the playlist size as a badge in the sidebar and fixed an appearance issue of the sidebar

macosx: converted interface builder files from nib to the more modern xib file format, which smaller and more suitable for git

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

There is no potentially cancellation-unsafe code here (unlike Qt4),
since msg_Free() is safe and vlc_mutex_*() of course too.

Contrary to C, C++ compilers don't promote larger constants up to
unsigned long long when needed.

No need to invoke vlc-config to expand a shell variable.

The lock is static anyway (and so is the data).

This is really poor implementation, but it is not really used.

 * No recursion within the VLC threading functions.
 * No need to care about VLC cancellation.

The overhead is negligible, and this avoids depending on the message
bank.

This saves over 1kb in libvlccore. This object was found with:

 # readelf -a src/.libs/libvlccore.so | grep OBJECT