Added two functions to check if smart charger if detected and enabled.
Modified functions to access them with doubles (time in seconds and Amperes).

Functions to access the smart charger module has been added to the driver of the Darwin robot.
Allows to enable or disable module, set and get period, get smart charger's data (average time to empty and to full
and battery status), read smart charger's control register (smart charger detected and/or enabled), write limit current.

Removed some unnecessary cout's.
Enhanced some of the examples to fully test all the features.

Solved a bug in the codification of some of the walk parameters.

Added an example to test the head tracking feature.

Added an example of use of the joints motion interface.

Added the current step to the action interface.

Removed the local copy of the dynamixel interface registers and used the firmware version.