gps todo - bug 376

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

time only mode
./bin/run.sh --set gps_operation 3

fix wake behavior when message arrives on lora

do new power measurements

fix has_gps based on new logic

don't send locations if the user has forbidden that (lie to phone so phone won't either)

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
make sure location still gets set once per boot and stays marked as valid on the gui 
send position updates super rarely
turn off checking for usb power and forcing always on
(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