updated variable names and values to be consistent with MIDI specification
Merge pull request #131 from algomusic/master

updated variable names and values to be consistent with standard MIDI specification

also, the rtmidi-scm file is part of the new pre-compilation infrastructure, which is still being tested (i.e. is in master, but not in the brew 0.52 version).  It'll be in 0.53.  So thanks for those changes as well.