Poco::TemporaryFile: fix possible naming collisions due to random zero increment

Foundation/include/Poco/TemporaryFile.h

@@ -40,6 +40,10 @@ class Foundation_API TemporaryFile: public File
 	/// The class does, however, delete the temporary
 	/// file - either in the destructor, or immediately
 	/// before the application terminates.
+	///
+	/// Note: Due to the way the temporary file names are generated,
+	/// collisions may be possible after 400-500 Million 
+	/// file names generated by a single process.
 {
 public:
 	TemporaryFile();