Debug addMessageToChannel() and getMessages().

Add:
	src/server_utils.c
		-debug addMessageToChannel() and getMessages(); fully functional, except
		the latter doesn't return the full length of the username of a submitted
		message (via packet; a message added directly by addMessageToChannel()
		returns the entire username).

	src/client_utils.c
		-add function to getMessages() from server

Mod:
	src/constants.h
		-increase MAX_PACKET_LEN from 1000 to 2000 bytes, for insurance.