- Committed Marco's block rewrite:

   + Blocks are not longer called if not rendered: major performance
     improvement.
   + Fixed some bugs (preview option was broken, path option was broken).
   + Removed "ascii"-type blocks.
   + Added permission to for "PHP blocks"
   + ...

  NOTES:

   + You'll want to run "update.php":

       ALTER TABLE blocks DROP remove;
       ALTER TABLE blocks DROP name;

   + You'll want to update your custom modules as well as the modules in
     the contrib repository.  Block function should now read:

       function *_block($op = "list", $delta = 0) {
         if ($op == "list") {
           return array of block infos
         }
         else {
           return subject and content of $delta block
         }
       }