Implemented SharedParameters system in the client (read more)

Here are more tweaks:
* InWorld's quit event now exits to the main menu, bypassing a relayed disconnect message
* InWorld's disconnect hander no longer throws exceptions (dropped creation packet bugfix)
* CombatData's internals now point to std::pair objects
* Enemies are stored in a global list

server/server_internals.cpp

@@ -33,6 +33,7 @@
 
 int ClientData::uidCounter = 0;
 int CombatData::uidCounter = 0;
+int EnemyData::uidCounter = 0;
 
 //-------------------------
 //Define the public members