Got ACL scope logic working again and began enforcing it. Breaking API change: assigning page title with $template->tpl_strings['PAGE_NAME'] will no longer work, use $template->assign_vars(). Workaround may be added later. Test for assign_vars method if compatibility needed. Added namespace processor API (non-breaking change). Several other things tweaked around as well.

# Used for testing mod_rewrite.
<IfModule mod_rewrite.c>
RewriteEngine on

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule (.*) install.php?do=modrewrite_test&str=$1
</IfModule>