. Added files needed for the forthcoming module management.
Notes:
Plugins are now called modules, because we will be able to compile
them either as a dynamic plugin, or within the program. And, more
important, I can commit this without having to break the vlc :)
I tried to be as clear as possible in my comments, please tell me
if a few prototypes still have an unclear beahaviour.
Current features:
. none, files haven't even been added to the Makefile yet.
Future features:
. dynamic loading (done)
. built-in modules (still to do)
. automatic unloading of plugins (done)
. dynamic configuration (still to do)
. automatic choosing of the most appropriate plugin for a given
task (still to do but well prepared)