Load map descriptions from their XML file.

Add basic hold-fire stance, and use it for some test maps.
Add JSON data container to map XML files, to simplify the interaction
between scripts and maps.
Fix fixed-point printing so it roundtrips safely through map files.
Fix camera startup positions in old-format maps.

This was SVN commit r7844.

source/scriptinterface/ScriptInterface.h

@@ -1,4 +1,4 @@
-/* Copyright (C) 2009 Wildfire Games.
+/* Copyright (C) 2010 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -29,6 +29,8 @@
 #include "ScriptTypes.h"
 #include "ScriptVal.h"
 
+#include "ps/utf16string.h"
+
 class AutoGCRooter;
 
 namespace boost { class rand48; }
@@ -154,6 +156,16 @@ public:
 
 	std::wstring ToString(jsval obj);
 
+	/**
+	 * Parse a JSON string. Returns the undefined value on error.
+	 */
+	CScriptValRooted ParseJSON(const utf16string& string);
+
+	/**
+	 * Stringify to a JSON string, UTF-8 encoded. Returns an empty string on error.
+	 */
+	std::string StringifyJSON(jsval obj);
+
 	/**
 	 * Report the given error message through the JS error reporting mechanism,
 	 * and throw a JS exception. (Callers can check IsPendingException, and must