MAVLINK Adaptation for SKY9X and 9xRPRO

Hi,
my name is Adriano and i modified v2.13 to
compile for sky9x with MAVLINK protocol.
It is working and i kindly ask you can include
these very little mods in mainstream.

Thank you for all your great job


note: i use slackware-linux(64bit) and gcc 4.7.3 and it compiles OK :-)