* how long can UI signal callbacks take to execute? What happens if they block?
where ENSURE_CORRECT_THREAD is a macro that is modelled on ENSURE_GUI_THREAD
if the handler is not called in the "correct thread", it will use a pseudo-RT-safe-enough technique to get the correct thread to recall "handler" later on, and return.
* finish button mapping
* discuss button mapping for Ardour
* concurrency for bank switching? And make sure "old" events aren't sent to "new" faders
* concurrency in write( bytes ). Queueing?
* Are remote_ids supposed to be 1-based or 0-based?
* TODOs in code
* handle remote_control_id changed signal from Route.
* handle removal of route. Need another session signal?
* Some indication on the UI of remote_ids?
Useful for surfaces that don't have a scribble strip.
* use i18n. see string_compose
* MackieControlProtocol in namespace Mackie?
* Generic surface code to common location
* power-cycling of surface. fd_midiport doesn't close.
* remove couts
* jog with transport rolling doesn't work properly
