Fix MTM sample fine tuning

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
Add missing Graoumf Tracker effects

Map arpeggio, set number of frames and set linear volume effects to
their tracker counterparts. Volume 0x100 was actually mapped to 0xff
due to limitations in effect parameter field size.

This should make neurologic.gtk play better. Module replay problems
reported by Misty De Meo.

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

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