- anchors have a new "lefttop" attribute, allowing them to follow the
       border of the window when resizing
     - the resizing is now handled by the WindowManager class (to enforce the
       mediator pattern). This makes it possible to handle tricky cases,
       such as:
           window B is anchored to window A, and A is resized
           ==> B moves accordingly, and can still be anchored by other windows

* Add a prefs button

 - simple screenshot function
 - an helper function to check if the input item is playing 

- vlcshell.cpp: make opengl the default video output module for macosx
- vlc.r: remove Quicktime mimetype from supported list
- configure.ac: the OpenGL provider requires the AGL framework

    automake naming scheme.

(Remove ITEMPLAY method, which had become redundant)

Quit

symbols that would be hidden by the visibility patch, thus allowing VLC usage
with patched FFMPEG code, and sanitise the need for accessing non-public
symbols. Patch by Diego Petteno (flameeyes at gentoo do org).