Fixed #56

_compile_session_data() is 'protected' to be able to extend
MY_Profiler.
diff --git a/system/libraries/Profiler.php b/system/libraries/Profiler.php
index 082a5ee..330acce 100644
--- a/system/libraries/Profiler.php
+++ b/system/libraries/Profiler.php
@@ -493,7 +493,7 @@
 	 *
 	 * @return 	string
 	 */
-	private function _compile_session_data()
+	protected function _compile_session_data()
 	{
 		if ( ! isset($this->CI->session))
 		{
@@ -555,4 +555,4 @@
 // END CI_Profiler class
 
 /* End of file Profiler.php */
-/* Location: ./system/libraries/Profiler.php */
\ No newline at end of file
+/* Location: ./system/libraries/Profiler.php */