Provide a 'bundle' token type to deprecate or help re-use tokens in [node:content-type], [term:vocabulary]

It's now become a pattern that we want to add a 'bundle' token type so that we can automatically provide tokens like [node:content-type], [file:type] (in file_entity). We can automatically provide [bundle:name], [bundle:machine-name], [bundle:count], and [bundle:edit-url] from hook_entity_info().