RR: add require-auth field to xform model
RR:  list orgs for which user has permissions, closes #398
RR: hide private forms and prevent submission from non-owners
RR: test submission to a private form by non-owner is forbidden.
RR: fix pep8
RR: revert response to bad request
PLD: code style cleanup
PLD: use require_auth instead of private
PLD: move instance create exceptions to separate helper function
PLD: try to pin bower version
PLD: remove require_auth check as it happens after the submission
PLD: test for submit to require_auth as anon and non authed user, skip test for authed user
PLD: assume xform and request exist (we do later anyhow) and check for require_auth on xform
PLD: revert removing check for request
Merge pull request #402 from onaio/322-update-form-sharing-levels

Update form sharing levels