Initial Commit

This is an updated version of the Dynon Interconnect board--with an
attempt to integrate a ground plane for shield grounding and trace
cooling.
Cleaned up grounds

Grounded all connector housings to bottom right mounting lug of CB; plan
is to connect that lug to the radio stack ground via a wire and ring
terminal.
Added exclusion around audio signal paths
Merge pull request #30 from lrgabriel/Grounded-Eagle-Board

Added ground plane to Dynon Interconnect