* (bug 22887) Add warning and tracking category for preprocessor errors
* (bug 31704) Allow selection of associated namespace on the watchlist
* (bug 5445) Now remove autoblocks when a user is unblocked.
+* Added $wgLogExceptionBacktrace, on by default, to allow logging of exception
+ backtraces.
=== Bug fixes in 1.20 ===
* (bug 30245) Use the correct way to construct a log page title.