- Minor build fix: debug vars were ifdef OVMS_DIAGMODULE
Twizy module version 2.6:
- Renamed local Twizy variables to avoid name space conflicts
- Battery monitor extended by stddev alert mode
- Power stats extended by distance / efficiency
- Minor bug fixes & changes

Note: introduced second overlay section "vehicle_overlay_data2"
 to circumvent C18 linker bug
Merge branch 'master' of https://github.com/markwj/Open-Vehicle-Monitoring-System.git