Add postgres build and allow it to fail.

refs #1333
Issue #1556 - Fix meta_title is undefined

Closes #1556 and #1530

This should also fix meta_description in #1530 as well as the other bug that is not
filed for body_class
Merge pull request #1559 from sebgie/failing-tests

Fix failing casper tests
Putting back relative redirects

issue #1523

- also added some comments to indicate the difference between the two custom middleware files.
Merge pull request #1557 from alicoding/issue1556

Issue #1556 - Fix meta_title is undefined
Create the config module, initially used
to standardise getting paths and absolute URLs.  Easy
to extend for other configurations we may need.
Merge pull request #1565 from ErisDS/redirect-fixes

Putting back relative redirects
Merge pull request #1535 from hswolff/create-config-module

Create config module to standardise getting paths and abs URLs
Merge pull request #1555 from halfdan/1333-allowed-failure

Add postgres build and allow it to fail.
Remove cookie from Frontend

closes #1437
closes #1472

- changed cookie to path:'/ghost'
- added conditional CSRF middleware
- added redirects for signup, signin, signout to /ghost/sign*/