Add AI script code to provide a cleaner API around the engine interface.

Handle AIProxy entirely through scripts.
Support structured clones of script values.
Improve performance.
Support multiple script contexts sharing a runtime.
Use a separate context per AI player.

This was SVN commit r8866.

source/network/NetServer.cpp

@@ -179,7 +179,7 @@ void CNetServerWorker::Run()
 {
 	// To avoid the need for JS_SetContextThread, we create and use and destroy
 	// the script interface entirely within this network thread
-	m_ScriptInterface = new ScriptInterface("Engine", "Net server");
+	m_ScriptInterface = new ScriptInterface("Engine", "Net server", ScriptInterface::CreateRuntime());
 
 	while (true)
 	{