Polish docs for HTML, Inflector, Language, Number, Path, Security and Smiley helpers

Also fixed a DB_cache bug introduced in previous commit and removed an unused parameter in a smiley helper
diff --git a/system/helpers/smiley_helper.php b/system/helpers/smiley_helper.php
index 6ae8937..4b49175 100644
--- a/system/helpers/smiley_helper.php
+++ b/system/helpers/smiley_helper.php
@@ -131,10 +131,9 @@
 	 *
 	 * @param	string	the URL to the folder containing the smiley images
 	 * @param	array
-	 * @param	array
 	 * @return	array
 	 */
-	function get_clickable_smileys($image_url, $alias = '', $smileys = NULL)
+	function get_clickable_smileys($image_url, $alias = '')
 	{
 		// For backward compatibility with js_insert_smiley
 		if (is_array($alias))
@@ -143,7 +142,7 @@
 		}
 		elseif (FALSE === ($smileys = _get_smiley_array()))
 		{
-			return $smileys;
+			return FALSE;
 		}
 
 		// Add a trailing slash to the file path if needed