Replaced boolean with enum in c'tor.

Implemented in a similar style to FPEnvironment.

Foundation/include/Poco/Mutex.h

@@ -49,9 +49,16 @@ class Foundation_API Mutex: private MutexImpl
 	/// lock and unlock a mutex.
 {
 public:
+	enum MutexType
+		/// The type of a mutex.
+	{
+		MUTEX_RECURSIVE = MUTEX_RECURSIVE_IMPL,			/// A recursive mutex
+		MUTEX_NONRECURSIVE = MUTEX_NONRECURSIVE_IMPL,	/// A non-recursive mutex
+	};
+
 	typedef Poco::ScopedLock<Mutex> ScopedLock;
 	
-	explicit Mutex(bool recursive = true);
+	explicit Mutex(MutexType type = MUTEX_RECURSIVE);
 		/// creates the Mutex.
 		
 	~Mutex();