Git: ignore generated files
Generates package version into version.h instead of config.h
Reduce minimal temperature to 60°c

This commit does fit a special need, please care about your design:
/!\ 60°C should be enough for indirect-injection engines but not recommended for direct-injection engines, specially high-pressured direct-injection types (ie. almost all cars from ~2005)
Toogle gauge light at startup
Uses git describe to enhance version info
Makefile: add 'make cppcheck' directive
UART: clean up files and set baud rate to 38400
Makefile: 'make reset' resets the target
Makefile: add size directive
Makefile: add style directive
make style
Arduino: preliminary steps to port utophuile to Arduino hardware

Makefile have been ajusted to work with Arduino hardware.
Note: flash is done throught AVRISP MKII programmer.

Some untested changes to make it compile:
 - adc.c
 - beep.c
 - buttons.c
 - leds.c

Gauge with RGB is no more a part of utophuile, so rgb.* have been removed.
Affected files are:
 - utophuile.c
 - rgb.*

Relay + TWI have been upgraded but do not have been tested with PCF, nevertheless relay connection status detect the missing PCF.
Affected files are:
 - relay.*
 - twi.c

Shell have been imported from bigaff project:
This provides a tiny human-usable shell (ie. use commands and have an help).
Affected files are:
 - shell.*
 - config.h
Makefile: use STK500v2 clone ISP
Beep: upgrade beep code to work on new hardware (Arduino)

 * Use a new prescaler as running frequency have changed (8 -> 16 Mhz)
 * Adjust notes fq using http://www.phy.mtu.edu/~suits/notefreqs.html
Remove internal ADC usage
Relay: Use generic twi_connection_state struct
TWI: add a comment to ease Arduino pins location
TWI: ease debuging with different error code
Code clean in utophuile.c
Beep: Set OC0 as output only in init()