Fixing bug in DB Driver where identifiers could be escaped in some drivers that can't accept it in the list_fields() function.

http://codeigniter.com/bug_tracker/bug/5865/
http://codeigniter.com/bug_tracker/bug/11218/
diff --git a/user_guide/changelog.html b/user_guide/changelog.html
index 4214a0d..713f012 100644
--- a/user_guide/changelog.html
+++ b/user_guide/changelog.html
@@ -75,6 +75,7 @@
 	<li>Database
 		<ul>
 			<li>Semantic change to db->version() function to allow a list of exceptions for databases with functions to return version string instead of specially formed SQL queries. Currently this list only includes Oracle and SQLite.</li>
+			<li>Fixed a bug where driver specific table identifier protection could lead to malformed queries in the <kbd>field_data()</kbd> functions.</li>
 		</ul>
 	</li>
 	<li>Helpers