Version 3 of timer: Support PWM, OC, and IC

This is my version 2 (not tested).

I verified it compiles.

It still needs the pin= support added.

It has PWM and OC support (adding IC and Encoder would be striaght forward)
> Also, oc_polarity is either OC_POLARITY_HIGH/LOW. We could change that to being True/False

I did it with 0/1 for polarity in SPI's init.  But you are right that it may not be as clear.