Prevent memory leak on MDL track allocation error

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
Comment out dead variable assignments

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
Refactor S3M arpeggio support

Create a true arpeggio effect with memory instead of supplying parameters
at load time, which can fail if the last set value resides in a previous
order.

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
[test] Update test data for new S3M arpeggio effect

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
Update changelog

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>