Get rid of id/uuid ambiguity for sellers/products (bug 942222)

The UUID is stored internally as ``_id`` and returned serialized as
``resource_pk``
Merge pull request #54 from davidbgk/942222-id-to-uuid

Get rid of id/uuid ambiguity for sellers/products (bug 942222)
Redirect to fail URL (bug 936126)
Remove unused docs
Document redirect API (part of bug 936126)
Merge pull request #55 from kumar303/fail

Implement fail redirects (bug 936126)
oops, these are used by doc renderers
Update bunyan
Convert to express
Move to errors for errors
Merge pull request #53 from muffinresearch/convert-to-express

Convert to express