Update changelog

CHANGELOG.md

@@ -1,3 +1,21 @@
+**MayhemYDG**:
+![New thread watcher](src/General/img/changelog/1.2.28.png)
+- Greatly improved thread watcher
+  - Added submenu with ability to prune 404'd threads, filter by current board, etc
+  - Periodically checks which threads have 404'd and indicates them with a strikethrough
+- Removed `Check for Updates` as your browser should now handle this automatically
+- Fixed an error for Firefox <23 users
+- Add a message for Chrome users who experience the Corrupted File bug
+
+**seaweedchan**:
+- Changed class `.fourchanx-link` for brackets to `.brackets-wrap` to be consistent with Mayhem's 4chan X
+
+**Zixaphir**:
+![Linkifier in action](src/General/img/changelog/1.2.28-2.png)
+- Drastically improved the accuracy and quality of the linkifier (with seaweedchan)
+- Removed `Allow False Positives` option due to the accuracy of the new linkifier regex
+
+
 ### v1.2.27
 *2013-08-12*