- Refactored the throttle module. Patch by Jeremy and me.

  * There are only two throttle levels instead of 5, namely 'enabled' and 'disabled'.  This makes it a _lot_ easier to predict when the throttle will kick in.  However, if you maintain a module that is throttle-aware, it needs to be updated!

  * The throttle mechanism now uses the current number of anonymous users or the current number of authenticated users to kick in.  This is a _lot_ more intuitive than the old throttle mechanism.

  * The throttle block has been removed -- you can now use the "Who's online" block to determine the good throttle settings.

  * Most of the documentation has been removed because it was deprecated.

  * It's less code!