Change errorHandler to webAlertQuit
- delete manager\includes\error.class.inc.php
- move lang from manager\includes\lang\errormsg\*.inc.php to manager\includes\lang\*.inc.php
- $e->setError() and $e->dumpError() changed to $modx->webAlertQuit()
- header/webalert/footer changed to $modx->webAlertQuit()
- echo and exit changed to $modx->webAlertQuit()