initial implementation to read ACS709 current sensor
[hexapower] SCT013-030 needs some more work
moved hallsensor code to seperate app
[hallsensor] adding missing folder
use the ADC interrupt instead of a contiki process to sample
fixed compile errors
added some debug output
use a different eid for hallsensor measurements (at least during debug)
move average calculation to interrupt handler
setup ADC only when hallsensor is enabled and initialize pos
[hallsensor] calculate the average of a second (50 values) to reduce noise
[hallsensor] refactored measurement code
[hallsensor] added value_broadcast every second
[hallsensor] calibration implemented
[hallsensor] type mismatch in calibration fixed
[hallsensor] make calibration persistent by storing the calibrated factor in EEPROM
[hallsensor] first check for !FAULT implemented
Merge branch 'development' of https://github.com/mysmartgrid/hexabus into sp-hexapower

Conflicts:
	firmware/contiki-2.x/platform/Hexabus-Socket/hexabus_config.h
[s0] removed webserver code for calibration and replaced it with a seperate endpoint
[hallsensor] fixed description for eid 21