Incorporate pedaling, snakebite accent data for 88-note rolls, correct or remove emulated acceleration

[broadwell]

This ticket is a catch-all for the improvements and fixes that eventually should be applied to produce "expressionized" versions of the 88-note rolls, and to make a cleaner distinction between the -raw and -note versions of these rolls, which should not contain any emulated expressions or acceleration, from -exp versions that do.