Added formatted printing

include/sta/debug/printing/printable.hpp

@@ -26,6 +26,12 @@ namespace sta
     class Printable
     {
     public:
+    	/**
+    	 * @brief fmt	The string defining the desired format.
+    	 * @breif ...	The parameters for the formatted string.
+    	 */
+    	void printf(const char * fmt, ...);
+
         /**
          * @brief Print single character.
          *