(svn r26349) -Add: Optional recursive locking of mutexes.

src/thread/thread_none.cpp

@@ -21,8 +21,8 @@
 /** Mutex that doesn't do locking because it ain't needed when there're no threads */
 class ThreadMutex_None : public ThreadMutex {
 public:
-	virtual void BeginCritical() {}
-	virtual void EndCritical() {}
+	virtual void BeginCritical(bool allow_recursive = false) {}
+	virtual void EndCritical(bool allow_recursive = false) {}
 	virtual void WaitForSignal() {}
 	virtual void SendSignal() {}
 };