Add extra tracker effects

[sm-Fifteen]

As it turns out, libopenMPT normalizes the effect IDs, so all that's needed is to find out which ones can be supported (considering we only have a pulse wave, so no volume or tremolo, n panning because no volume, and can't update it too often).

From modcommand.h :

• CMD_ARPEGGIO = 1
• CMD_PORTAMENTOUP = 2
• CMD_PORTAMENTODOWN = 3
• CMD_TONEPORTAMENTO = 4
• CMD_VIBRATO = 5
• CMD_PATTERNBREAK = 14 // Immediately jump to next pattern
• CMD_RETRIG = 15 // Retrigger every n Ticks
• CMD_SPEED = 16
• CMD_TEMPO = 17
• CMD_KEYOFF = 25 // Turn off after n Ticks

The rest mostly seem to be fine versions of existing commands, but I might have missed some.

[sm-Fifteen]

Vibrato is gonna need some more work, but it's there, so I'll mark it as done.

[Teteros]

CMD_TEMPO and CMD_SPEED would be really handy as some modules straight out sound wrong because they rely on those effect.

e.g: Start of Chain Chip https://youtu.be/5DRLLsBitIU?list=PLdKuLQHTZCh_j6mmfSSmlxOuHWuXbmUdK

What you already have is quite impressive and I'm having a blast with it!

[sm-Fifteen]

Yeah, I should probably priorise those two. Looking at your other videos, the pattern break command (CMD_PATTERNBREAK = 14) also breaks a few songs, so I added it to the list. I'll see if I can't find some time next week to add those three.

Glad you're having fun with it, in any case.