#201141 by yched: instead of 'HTTP error 200' messages when a PHP error occurs, actually display the PHP error message

#184867 by deekayen, catch and keith.smith: fix some spelling errors in our source code and messages printed

#181741 by quicksketch: fix AHAH throbber/progress bar issues and generalize progress display configuration to allow module developers to choose from the throbber and progress bar

#157752 by quicksketch: extend AHAH functionality to most types of form elements, without writing JavaScript. Also AHAH enable the blocks admin page.

- Patch #154398 by quicksketch et al: add dynamic AHAH submission properties to Forms API.  This patch was ready for a long time and is somewhat of a usability improvement (enabler).