Optimization: When checking user capabilities, return early for "do_not_allow" since nobody should have that capability under normal circumstances.
Optimization: Skip checking $item_templates['access_level'] if the "custom_admin_menu_capability" filter has already determined that the user should have access. This only applies to the Pro version, the free version doesn't use that filter.

git-svn-id: https://plugins.svn.wordpress.org/admin-menu-editor/trunk@817336 b8457f37-d9ea-0310-8a92-e5e31aec5664