
Ideas for a new registry system:

- each plugin has an associated registry XML file.  Each xml file in
  a plugin directory is loaded to create the in-core registry.

- needed for avidemux:

  <Company> plugin x create some registry information that says stuff like:
  <Company> "caps x are fourcc FOOO in avi"
  <Company> or "caps y may be contained in id3 tagged files"
  <Company> or "caps z is a valid format to put in an ogg container"