stabilize messages/meta

Created by: metakeule

There are some open questions regarding the stabilization of messages/meta:

Naming issues

"Copyright" or "CopyRight"?
"CuePoint" or "Cuepoint"?
"Sequence" or "SequenceName" or "TrackName" or "Track"?
"TrackInstrument" or "InstrumentName" or "Instrument"? (should not be confused with program that in GM is assigned to an instrument (and a channel at some time), tracks however may contain data for different channels, so also for different instruments, so the proper naming would probably be "Track", however that may be confused with Sequence which may also be denoted as "Track")

other things