TEMP: attempt to fix io-comm
Use grunt-mocha-test instead of grunt-cafe-mocha

Much better error/debugging output
Send dedicated command as response on I/O changes triggered by host

DeviceCommunication.sendCommands expects one response per command,
and we need to be able to ignore the commands which are not responses
to host-initiated messages
DeviceCommunication: Don't treat debug+iochange as response, emit commands also when not sending
DeviceCommunication: Fix invalid end of transmission message