such as program changes and pitch bend. Also add error handling for invalid
parameter values such as MIDI channel. This however makes a somewhat breaking
change to the current implementation, in that we now use the typical MIDI user
system of counting MIDI channels from 1-16 instead of from 0-15 as the lower
level USB-MIDI API itself expects.
Also add constant values for continuous controller messages, rename SendCC
function, and add SysEx function.
Signed-off-by: deadprogram <ron@hybridgroup.com>