Set tempo

Tracker 4.44

### 15 Set tempo

If 0 <= para <= 31, set t1=para, reset t2 to 125. Else, set t2=para (for Protracker). Older trackers don't ever change t2, but always set t1=para. Special value 0 is supposed to end the module with Protracker.
Special case: several set speed commands in the same events. The later ones do take precedence upon the earlier ones if both are supposed to affect t1 or t2. If one set speed command affects t1 and the other t2, the most likely guess is to set t1 and t2 accordingly, but you can't be sure... you have to either provide some switch to change your player behavior according to the value you got, or to apply some heuristic to go on playing... See Soundtracker and Protracker tempo, for more details.

Scrolling mode:

         1 A-4 SPD 7		(for t1 tempo)
      	1 A-4 spd%95	(percentage of normal finespeed)