Buildsystem: Add PCH-support for targets shared, collision, authserver and worldserver (your mileage may vary, feedback needed)

- The active configuration for these to be active is GAMEPCH, so don't expect turbospeed if not enabled.

--HG--
branch : trunk

src/server/game/PrecompiledHeaders/gamePCH.h

@@ -1,5 +1,7 @@
 //add here most rarely modified headers to speed up debug build compilation
-#include "WorldSocket.h"                                    // must be first to make ACE happy with ACE includes in it
+
+#include "WorldSocket.h"        // must be first to make ACE happy with ACE includes in it
+
 #include "Common.h"
 
 #include "MapManager.h"