a few improvements

Found an issue that may be the cause behind the RTC not working - one of
the sleep commands set the system into LPM2 while the wake-up
instructions are recovering as if it had been in LPM0, therefore leaving
some of the clocks disabled.
Also implemented some reduced-functionality power-saving methods to
prevent brown-outs.
lab testing

Changes made during lab testing. Increased PWM period and increased the
wakeup timer period. Also removed the "|=" ADC assignments
merge conflicts...

Trying to fix merge conflicts...
lab tested improvements

Many improvements have been made, notable some framework for receiving
commands has been added and a transmit power modifier attempt has been
made. It is not yet clear from testing that our transmit power modifier
is working correctly. Also, several modifications were made to try to
improve brown-out recovery.
Improved RSSI handling

More lab testing was done. Discovered 32khz oscillator that drives the
RTC is not populated. Also, discovered that RTC is given as a signed
integer, therefore the control was modified to utilize it correctly. We
have not done a full auto control loop yet for transmit power, but I
think it will be unstable when we do....
feedback-controlled TX power

The automatic feedback-control scheme for minimizing TX power is now
working and stable.
Merge pull request #4 from kjgregory/master

feedback-controlled TX power is implemented