Fix #739 (test failures).

Use JSON in debug serializer output unless it fails due to e.g. cyclic
values, in which case use toSource.
Disable file stats code by default, since its output isn't used.

This was SVN commit r8975.

source/scriptinterface/ScriptInterface.h

@@ -200,7 +200,7 @@ public:
 
 	template<typename T, typename CHAR> bool Eval(const CHAR* code, T& out);
 
-	std::wstring ToString(jsval obj);
+	std::wstring ToString(jsval obj, bool pretty = false);
 
 	/**
 	 * Parse a UTF-8-encoded JSON string. Returns the undefined value on error.