gps todo - bug 376

for taiwan region:
bin/run.sh --set region 8

fix poll interval for sending commands to ublox

change defaults to 2 min 

properly handle time only modes

force gps sleep when in LightSleep and force wake only once <- confirm

fix has_gps based on new logic

have loop methods return allowable sleep time (from their perspective)
increase main cpu sleep time

add set router mode in python tool - it will also set GPS to stationary
(which will shrink DARK and NB period to zero and
 make light_sleep very long)

warn people about crummy gps antennas - add to faq

gps states

Active - for gps_attempt_time seconds
Sleeping - for (gps_update_rate or sleep forever) seconds
ForcedSleep - PowerFSM says we don't want to use GPS right now
(no need for sleep forever state)

gps triggers
GPS_TRIG_FORCE_SLEEP - from powerfsm
GPS_TRIG_FORCE_WAKE - from powerfsm
GPS_SETTINGS - if GPS settings changed, reset params and possibly become active