Changed a massive swap statement for bounds checks

Instead of using a massive block of case statements in serial_utility.cpp,
I've added FORMAT_* tags to SerialPacketType as a way to destinguish
between type values, at least internally. I can't believe I missed this
for so long.

I've also added a placeholder for the network API, as I was working on
that when I ran into this problem.

common/network/serial_packet.hpp

@@ -34,7 +34,7 @@
 typedef SerialPacketBase SerialPacket;
 
 //DOCS: NETWORK_VERSION is used to discern compatible servers and clients
-constexpr int NETWORK_VERSION = 20150214;
+constexpr int NETWORK_VERSION = 20150221;
 
 union MaxPacket {
 	CharacterPacket a;