public.json: Add 'POST /routes' to create a new route

The newRoute schema still needs to be filled in.  See the discussion
in 03e139a0 (public.json: Add 'POST /drops' to create a new drop,
2014-12-19) for details.
public.json: Add 'PUT /route/{name}' to update a route

The data should match the usual 'route' schema.  In this case, I don't
mind if folks set the 'name' property or not (whichever is easiest),
but if they set the 'name' property it must match the name used in the
URL.

Returning the updated route doesn't seem useful (it should be
semantically equivalent to the uploaded data), so I've gone with '204
No Content' as the default success response.
public.json: Add 'DELETE /route/{name}' to delete a route

Returning the deleted route doesn't seem useful (if you want more
information about it, ask before you delete it ;), so I've gone with
'204 No Content' as the default success response.
Merge branch 'route-CrUD'

Create, update, and delete endpoints for routes.

* route-CrUD:
  public.json: Add 'DELETE /route/{name}' to delete a route
  public.json: Add 'PUT /route/{name}' to update a route
  public.json: Add 'POST /routes' to create a new route