Since I want to segregate the code according to the domain,
several methods must be provided to the video display to conduct
a properly synchronised handover of video pixel data; by using
`Glib::Dispatcher` as base class, all aspects of feed synchronisation
can be packaged into a single connection interface, without having
to share implementation details between the video display and player.
leaning heavily on the similar structure used for last year's
FrOSCon talk regarding video output (by Benny Lyons and myself).
However, this time we'll use a process state object (the player)
and, furthermore, there is some cross-wiring of components involved...
