ability to raise FOI requests

before this change, FOI requests were raised by the 'feedback' app
directly into Zendesk. This change allows the 'feedback' app to make
API POSTs for FOI requests being submitted by the public, with the
'support' app then raising it with Zendesk
restrict FOI request access to api users
foi requests: response on error
don't redirect on new JSON request submission

this saves the REST client having to pointlessly follow a redirect
add missing newline
Merge remote-tracking branch 'origin/foi_requests'