. made the audio_output API a bit simpler.

 . got rid of modules_config.h.

 . fixed `make install' rule.

 . fixed warnings in the MMX YUV compilation.

 . probably fixed a bug in the input : pp_foo structures were free()d at
   the end, but this was useless since the last call to realloc() is
   equivalent to free(), and two consecutive calls to free() aren't a
   goo idea.

 . we check that the version number match and that we don't already have
   a module by that name when loading a new module.

 . all public module_* functions now properly lock the module bank.

 . the audio_output now uses the new module API ; EsounD and DSP modules
   have been ported, which should be enough for Henri to port the ALSA one.


   The new plugin API is now much simpler ; it's now just a matter of
calling module_Need( p_main->p_module_bank, MODULE_CAPABILITY_FOO, p_data );
and if successful we get the best module. Capabilities can be ORed, so that
one can ask for a plugin that does VOUT _and_ INTF actions for instance.

   It's not complete yet though -- by making it generic I had to do a few
ugly casts here and there, which I am going to fix ASAP. Also, command line
selection of a plugin does not work yet.

   The switch to the new plugin API has probably broken the BeOS audio
output ; we can either wait until the whole vlc has switched to the new
plugins, or create a separate beos_sound.so that conforms to the new API.