Drupal 7 now supports extension based fast 404s [#1313592]

Thanks to Ralf for pointing out that the original genesis for this module has now finally made it into D7 core. The issue that spawned this and contains the patch that was applied to D7 is: http://drupal.org/node/76824?page=1. The patch is here: http://drupal.org/files/issues/404_fast_paths_7x-76824-328.patch

What this does is (much like Fast 404) define some excluded paths, some paths to check, and the fast 404 HTML.

$conf['404_fast_paths_exclude'] = '/\/(?:styles)\//';
$conf['404_fast_paths'] = '/\.(?:txt|png|gif|jpe?g|css|js|ico|swf|flv|cgi|bat|pl|dll|exe|asp)$/i';
$conf['404_fast_html'] = '<html xmlns="http://www.w3.org/1999/xhtml"><head><title>404 Not Found</title></head><body><h1>Not Found</h1><p>The requested URL "@path" was not found on this server.</p></body></html>';

I plan to make the D7 version of the Fast 404 module also look for these variables if its own are not set. That way (at a future point) we can consolidate on these new variables.

New versions of D7 will have these 3 variables defined in the settings.php, and then at the point in bootstrap (I think its stage 7) where it delivers the 404 page, it will call this function (http://api.drupal.org/api/drupal/includes--bootstrap.inc/function/drupal...) and exit.