- property proxy in compount elements.
- implement events in all plugins.
- app must be able to catch events?
- deal with clocking issues
- use real chaining where possible
- factory aliases?

* gst_elementfactory_make ("factoryname", NULL) automatically uniquifies the name
* a plugin test rig
* parser and scheduler test system
* clean up xml code - restore/save creates/save pipeline, gst_object_save/load_props 
  with just the properties
