this needs to be tested

* more synchronization with playlist and input threads
* new libvlc functions binded

* video.c: added 1 release object in GetVout
* input.c: added libvlc_get_input_thread helper

* video height/width retrieval
* input playing status check

* Add notify plugin

Thanks to xtophe

* libvlc playlist play uses locking

Automake 1.5 and 1.6 both suck, and 1.7 is almost four years old, so there is really no excuse for not using a decent version. Besides, there seems to some problems while building the loader with old Automake versions.

This simplifies the build system quite a lot, and reduce compilation
times when PIC is actually needed.

If you really mind the extra overhead of PIC, use:
./configure --enable-libtool --enable-static --disable-shared

* --enable-pic added in configure.ac
* bootstrap modified to use BUILD_PIC in place of BUILD_MOZILLA where needed

   Observer classes now has a default value. This simplifies the code in many
   places.

* Improve notification layout

TODO: - get rid of the harcoded path for the icon
      - make the meta printed an option.

     - 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