Added some docs to CI core files
diff --git a/system/core/Output.php b/system/core/Output.php
old mode 100644
new mode 100755
index 05ace91..ccecafd
--- a/system/core/Output.php
+++ b/system/core/Output.php
@@ -28,15 +28,67 @@
  */
 class CI_Output {
 
+	/**
+	 * Current output string
+	 *
+	 * @var string
+	 * @access 	protected
+	 */
 	protected $final_output;
+	/**
+	 * Cache expiration time
+	 *
+	 * @var int
+	 * @access 	protected
+	 */
 	protected $cache_expiration	= 0;
+	/**
+	 * List of server headers
+	 *
+	 * @var array
+	 * @access 	protected
+	 */
 	protected $headers			= array();
-	protected $mime_types			= array();
+	/**
+	 * List of mime types
+	 *
+	 * @var array
+	 * @access 	protected
+	 */
+	protected $mime_types		= array();
+	/**
+	 * Determines wether profiler is enabled
+	 *
+	 * @var book
+	 * @access 	protected
+	 */
 	protected $enable_profiler	= FALSE;
+	/**
+	 * Determines if output compression is enabled
+	 *
+	 * @var bool
+	 * @access 	protected
+	 */
 	protected $_zlib_oc			= FALSE;
+	/**
+	 * List of profiler sections
+	 *
+	 * @var array
+	 * @access 	protected
+	 */
 	protected $_profiler_sections = array();
-	protected $parse_exec_vars	= TRUE;	// whether or not to parse variables like {elapsed_time} and {memory_usage}
+	/**
+	 * Whether or not to parse variables like {elapsed_time} and {memory_usage}
+	 *
+	 * @var bool
+	 * @access 	protected
+	 */
+	protected $parse_exec_vars	= TRUE;
 
+	/**
+	 * Constructor
+	 *
+	 */
 	function __construct()
 	{
 		$this->_zlib_oc = @ini_get('zlib.output_compression');
@@ -127,6 +179,7 @@
 	 *
 	 * @access	public
 	 * @param	string
+	 * @param 	bool
 	 * @return	void
 	 */
 	function set_header($header, $replace = TRUE)
@@ -265,6 +318,7 @@
 	 * benchmark timer so the page rendering speed and memory usage can be shown.
 	 *
 	 * @access	public
+	 * @param 	string
 	 * @return	mixed
 	 */
 	function _display($output = '')
@@ -401,6 +455,7 @@
 	 * Write a Cache File
 	 *
 	 * @access	public
+	 * @param 	string
 	 * @return	void
 	 */
 	function _write_cache($output)
@@ -452,6 +507,8 @@
 	 * Update/serve a cached file
 	 *
 	 * @access	public
+	 * @param 	object	config class
+	 * @param 	object	uri class
 	 * @return	void
 	 */
 	function _display_cache(&$CFG, &$URI)