o add missing channel flags for ECM, indoor, and outdoor constraints
o use HT capabilities to short-circuit HT20/HT40 channel construction
o rewrite 1/2 and 1/4 width channel handling yet again; previously
we assumed there was a full-width version of the channel in the
calibration table but that's not always true (e.g. for the Public
Safety Band), now we first check the calibration table for the
exact channel we want then fall back to the heuristics we used before
o fix HT channel construction; wasn't adjusting band edges for HT40
channel bandwidth requirements
47ee60ebbe