Attempt to make client gmcp to server communication working.
Adjusted memory strategy of json conversion.
Handle invalid json and packages without payload.
Handle errors during the incoming_gmcp call.
Allow input_to to be called without arguments, and let it cancel any active input_to's.
Revert "Allow input_to to be called without arguments, and let it cancel any active input_to's."

This reverts commit 76b4e11871a7d9ac38f80a3790b05764994dcb3e.
Merge remote-tracking branch 'eowul/gmcp' into gmcp

Conflicts:
	telnet.c