The trouble with having:
/tags/:tag_id/...
and:
/tags/intersection/*tag_ids
for example, is: what happens if you want a tag called intersection?
Under this new scheme. Routes referring to a single tag are unambiguous
because they are prefixed with:
/tag/:tag_id
Routes referring to the collection of tags still start with:
/tags/
This commit just adds the new routes. It doesn't remove the old ones or
cause the new ones to be used.
1fb7a6297c