Add support for multiple measurables per sensor

This will be used, e.g., in the case of GPS, where the sensor can
produce a latitude, a longitude, and an altitude.
nmea: Initial commit
config: Test nmea
Hacks for testing
data-logger: Chunk sample downloads
Further separate measurables from sensors
README: Update
data-logger: Fix erase command
Print all measurables in `l` command
Rip out binary print sample
bmp085: Initial commmit
Move all sensors to sensors/
Split up sensors/temperature
README: Language tweak
README: Some notes about power management