Created the smart charger module files

Implemented an API for the smart charger.
This module it's in charge of the smart charger device connected to any of the Dynamixel bus of the sub-controller of the Darwin Robot.
It provides a set of functions that allows the user to enable or disable the module and change or obtain the smart charger's period,
this means the time to perform a read access of the smart charger's and batteries info.

On the other hand, it implements a periodic reading of part of the memory map of the smart charger to obtain the batteries time to full
or time to empty. This information is used for an automatic battery charger application.
Other battery information (as current consumption, voltage, etc) is also available with this structure.