- property proxy in compount elements.
- plugable schedulers.
- implement events in plugins.
- app must be able to catch events?
- caps nego
- propagation of errors in plugins.
- deal with clocking issues
- use real chaining where possible
- factory aliases?

* autoconf testing :

- SDL : seems to be ok now, test
- rtp : weird problem, can't get it to work with AC_CHECK_HEADER(S)
- arts : rh72 has artsflowh. in /usr/include/kde/arts
  	 there's no arts-config
	 so what do we do to find it ?