Client can now actually send messages via command

Client can now specify the recipient of a message and type it. Messages for offline users are saved, unaccesible for now.

Makefile

@@ -5,11 +5,11 @@ all: client server
 
 client:
 	mkdir -p build
-	$(CC) $(CFLAGS) -o build/client client.c
+	$(CC) $(CFLAGS) -o build/client client.c util/util.c
 
 server:
 	mkdir -p build
-	$(CC) $(CFLAGS) -o build/server server.c
+	$(CC) $(CFLAGS) -o build/server server.c util/util.c
 
 clean:
 	rm -f client server