Added a general configuration file for all modules (darwin_conf.h).

GPIO modules tested.

Changed the gpio module to reduce the code repetitions and reduce code size.
Darwin time module now using timer 8.
Added timer 1 to the ADC module to be able to tune the sampling period.
Scheduler module no longer needed but not removed yet.

Chnaged the dynamixel slave module to the version 2 of the protocol.
Added header files of rthe register definitions and eeprom initialization values.
Added a scheduler to time several tasks with a single timer.
Removed some old files.