Added the ability to save RAMPZ and EIND registers (Atmega2560 has it)
Update repository DuinOS and Master Branch to reflect the work of the
Arduino repository in the same branch and FreeRTOS upgraded to 7.4.0.

To check the details of the changes CarlosDelfino repos / Arduino in
Master branch.
Merge pull request #2 from niesteszeck/Mega2560

Added the ability to save RAMPZ and EIND registers (Atmega2560 has it)
Fixed storage register R0 to other AVRs than the ATmega 2560.
the macro portRESTORE_CONTEXT () when used for other AVRs that are not
the type ATmega 2560 has a fault after the last fix, replicating the
storage R0 registered two consecutive unnecessarily.
Merge branch 'master' of https://github.com/carlosdelfino/DuinOS

Conflicts:
	arduino.DuinOS/DuinOS/port.c