10 - in memory (trivial?)
13 - provide API to the core to load/inspect/save plugins.
14 - provide user/system registry
15 - provide combination of backends
16 - provide backend specific queries
20 There are two be two registries on the system. One system registry and one user registry.
21 The user registry should be queried first, then if that doesn't exist or don't contain any
22 plugins able to handle the mediatype it should fall back to system registry.
29 !---> registry (name, priority)
32 !---> registry (name, priority)
43 A registrypool holds a list of registries each with a priority
45 A registry contains a list of plugins (or libraries)
47 A plugin contains a list of features (elementfactories, typefacories, ...)
49 Loading the registry will do
51 - instantiate empty GstPlugin objects (loaded flag == FALSE)
52 - instantiate empty plugin features