Plugin:
- get info about play state, URL etc back from viewer to the plugin
- support all <embed> and <object> attributes that the legacy plugins support
- there still seem to be some unnecessary symbols exported in the plugin .so's
- use peer-2-peer DBUS instead of session bus
- (maybe) use libdbus directly instead of dbus-glib
- unify playlist handling into the viewer (is it possible to write a gstreamer element
  that handles the playlist internally?)
- make StreamAsFile use async calls; need to keep a link to the file around!!
- put back narrowspace URL extension parsing
- use nsCOMPtr<> once the linking has been figured out (libxpcomglue_s)
- invert DBUS-OpenStream/NPN_GetURL order: this is necessary so we can push the real stream URI
  to the viewer (for use as base uri for redirects)

Viewer:
- show totem logo image when waiting for click to start?

GMP plugin:
- write IDL files (where [_not_ MSDN !] to find documentation?)

Complex plugin:
- write IDL file (nsIHXPlayer.idl available, but incompatible with totem's
  licence exception; is the exception needed for the *plugin* itself?)
- implement the various 'controls' types in the viewer
- in the viewer, cope with the 'main' window being removed? (maybe reparent to a hidden window)

NarrowSpace plugin:
- write IDL file (where to find documentation?)
