Merge pull request #24 from thomasjfox/master

APC will be updated in 5 minutes ;)
Added config variable "pas_magnets" accounting for different PAS sesors. When using a Thun X-Cell RT do not forget to set this to 8.
fixed throttle issue when no PAS sensor configured
Added variable "odo" counting the overall kilometers of the bike, stored in eeprom. To get the actual value in km multiply odo with wheel_circumference/1000.
Make new odometer variable unsigned