clarify fader labels
fix meter(s) when mixer-strip is switched to AuxSend
add a hack to deal with device discovery race, in which the devices were not actually known to be ready before the last update_surfaces() call (which is where binding between strips and routes occurs) ; add support for Mackie Control touch on/off messages
clear up some stupid thinking in Amp regarding the way the underlying AutomationControl/Controllable gets set when Amp::set_gain() is called
add option to skip guard points when adding new control points to a ControlList; add more debugging statements
do not needlessly keep starting touch/automation watch passes just because a command to start or stop touch was received
use new ControlList::add() argument
ctrl-click when adding automation points no longer adds guard points
add a hack to deal with device discovery race, in which the devices were not actually known to be ready before the last update_surfaces() call (which is where binding between strips and routes occurs) ; add support for Mackie Control touch on/off messages
Revert "add a hack to deal with device discovery race, in which the devices were not actually known to be ready before the last update_surfaces() call (which is where binding between strips and routes occurs) ; add support for Mackie Control touch on/off messages"

This reverts commit 06a25ffd5695697db9869a19e46c2f93c6c17458.
click (no drag) on automation line now adds a new control point on the line (not fully checked for precision)
fix prev_snap_choice() key="3" binding
the forgotten second (amend to prev commit)
add the with-guard-point distinction to region gain lines (imported from cairocanvas)
reverse default behaviour for adding control points to automation with mouse clicks. unmodified click adds new control point without guard points; ctrl-click adds new point with a guard point (old behaviour)
(backport from cairocanvas branch) do not crash when considering a directory called midi (with any case) as an apparent MIDI file
clarify A/V import options
tweak A/V import logic
videotimeline: fix black-frame generation (sample aspect ratio) on export
Add option to display the mixer in fullscreen

This is useful for dual-head setups.