Adds CSP header for security in nginx server

[phantomjinx]

• HAWNG-517 - Adds CSP headers to nginx server

[phantomjinx]

CSP headers included in response

[phantomjinx]

One comment. Also it seems this is mixing two different fixes in one pull req, which blocks merging the ok part. Please split it into two.

Done.

PR for /master access control is now here