Added category shortcodes to allow easy modification of which categories are shown. Added shortcode to menu index. Added link to items index on item edit. Fixed minor encoding bug on menu XML RSS feed. Combed through plugin functions with debug on to remove warnings.

git-svn-id: https://plugins.svn.wordpress.org/easy-restaurant-menu-manager/trunk@870418 b8457f37-d9ea-0310-8a92-e5e31aec5664