[LV2] FM Synthesis Vocabulary

[jordan at halase.me]

Hello all,
 
I have added common FM synthesis vocabulary to LV2 Parameters. The commit can be seen on my own github.

https://github.com/jordanhalase/lv2/commit/3c333c22b4c0c8d90580ff1ac91e96174023ec83

Nearly every FM synthesizer in existence has a "frequency ratio" and "frequency offset" parameter for each oscillator in the system. They are of crucial importance to describing FM patches. It would be useful if LV2 could describe them.

Any thoughts? questions? modifications?

-Jordan Halase