Metadata optimizations

Building on https://github.com/TauLabs/TauLabs/pull/356, this optimizes update rates for sensor calibration, transmitter calibration, and HiTL simulation.

All functions tested and perform as expected. This includes canceling out of the whatever task is manipulating the metadata (Note, the transmitter functionality was not tested through to the very end, because without a transmitter I couldn't reach the last few pages. I'll do the full transmitter test tomorrow.)

The calibration gains make leveling, six-point, and variance tests 2.5 times faster. The transmitter calibration gains will be harder to see, but I also solved a bug in the calibration process that left the user waiting in one of the wizard pages. Lastly, the increased HiTL telemetry rates will reduce setup efforts required for doing high-accuracy simulations.

EDIT: I forgot to say that I can just as easily split these up into three separate reviews. I kept them together since it's effectively the same approach applied three times over. Let me know if it's uncomfortable to review this because of its size, or if it helps to be able to see all the similar changes at once.