Update to ssbMonoADSR

Updated code to use same methods/logic as the ADSR_EX code.
Fixed A number of bugs.
Updated the timing calculation code for attack, decay and release.
ssbMonoADSR_EX

Modified from original to support sustain on A2 and gate in on A4
Re-write envelope state support.
Refactored loop into more supportable helper functions.
Fixed A number of bugs.
Updated the timing calculation code for attack, decay and release.