the rest from `tools/convert_boost.sh`.
* replace boost::function, boost::bind with std::function and std::bind.
This required some manual fixes, notably std::placeholders,
some static_casts<>, and boost::function::clear -> = {}.
* add an option to the controller configuration gui
to assign the 3x2 send banks in mixer mode
to either the upper (1-6) or lower (7-12) Mixbus sends
* This was a user request to better support the workflow
of the CoMondo Mix system
In the Controller's settings you can now
choose between two operation modes:
1) 8 track mode
2) 7 track plus master mode
In case 2) fader 8 is fixed on the master
