Include csrf token in jade templates.

CSRF protection is important to any web app.
Add check for Express 'trust proxy' setting and enable/disable accordingly
Update docs to reflect addition of 'trust proxy' configuration setting
Restore previous whitespace in index.js
Restore previous whitespace configuration.jade doc page
Merge pull request #248 from crimeminister/feature/express-trust-proxy

Feature/express trust proxy
Add dependency on 'range_check' library
Default the 'allowed ip ranges' option to env.ALLOWED_IP_RANGES
Detect option 'allowed ip ranges' and bind middleware accordingly
Add lib/security.js containing ipRangeRestrict middleware
Merge pull request #254 from crimeminister/feature/ip-range-restrict

Add IP range-based access control
Set up tests and add them for Path.
Merge pull request #255 from moll/refactorings/tests

Set up tests and add them for Path.
Merge branch 'master' into add-csrf-protection
Add S3_REGION parameter for non default S3 regions
Merge pull request #262 from DrMoriarty/master

Add S3_REGION parameter for non default S3 regions
Merge pull request #263 from metasansana/add-csrf-protection

Add csrf protection support to admin templates
Updating the site footer with Thinkmill credit
Cleaning up index.js a little and exposing express on the keystone instance
Fixing inclusion of _csrf token and field