TempoMap::get_grid() supplies a list of beat positions, leaving the lines
to work out any subdivision positions.
This is fine, unless a tempo section falls in between beats.
Use a BeatsFramesConverter along with a quarter note position
(in the BBTPointsList) to make this easier.
Since 478f26b2ad, transport_rolling() is only true when actually rolling.
Count-in is a no-roll process (don't move playhead, no playhead UI
position interpolation 55b8b448).
But transport isn't exactly stopped either (preparing to roll), so
during count-in transport_stopped() == transport_rolling() == false.
The property names with underscores are "normalized" to replace the underscores
with hyphens in the XMLProperty constructor from within Meterbridge::get_state
and so have always been written with hyphens.
These property names have been "normalized"/changed to use a hyphen in the
XMLProperty ctor since 2008. That is before the Meterbridge existed so there
should be no files existing that contain these properties with underscores.
These are normalized in the PBD::XMLProperty ctor, which is why
Editor::get_transport_controllable_state() uses the hyphenated names to
retrieve the properties and will not result in any state format change.
cfgtool was used to dump the current config defaults into ./system_config
on the system it runs. It was manually invoked (usually on Linux) and
hence produced incorrect settings for Windows and OSX variants.
Since ea4bbcf5 Ardour binaries bundle a minimal empty system_config,
and the built-in defaults are used (correct for every platform).
The Editor continues to notify them, but via a direct call to ControlProtocolManager, not a signal.
The CP Manager calls the ControlProtocol static method to set up static data structures holding
selection info for all surfaces and then notifies each surface/protocol that selection has changed.
This prevents various edge-cases of selection-clocks (eg. unbound range
selection after start-range; and makes it near impossible to roll-over
2^63 using GUI operations)
