Fix getMessages() memory bug.

Fix:
	src/client_utils.c
		-a malloc'c char pointer was never freed
Fix changing time bug.

Fix:
	src/server_utils.c
		-getMessages() prepended every stringified, outgoing message with
		a sprintf'd time(NULL), instead of that Message_t's time_t
		-hence, the time displayed client-side was always the current time,
		not the time at which the message was actually sent
Functional client-to-client communication.

Add:
	src/server_utils.c
		-fix main memory leak by mallocing each message's string components
		(username, message).