Just naming changes: rocid -> roci2c just to be more explicit on what
we use to address the chips.
Make getenabledcolumns aware of I2C addresses and select the right ROC
Correctly send the I2C address to the HAL, not the internal ROC id
Make expandLoop aware of FLAG_FORCE_MASKED. First part of fixing #96
Rework MaskAndTrim() to correctly work with FLAG_FORCE_MASKED, now completely
relying on the I2C address instead of the more-or-less random internal ROC id.
Adding new function to work on single ROCs instead of the full DUT. This should
fix #96.