Implement specs and implementation for setting, getting, and rendering variables in the Google Tag Manager data layer.
Loosen up multi_json dependency to ~> 1.8.0
POC of GTM event registration
Squashed commit of the following:

commit 2367fd8498ab089a54ad861bc3d433e1723ebd9d
Author: Daniel Pehrson <dpehrson@qurve.com>
Date:   Fri Feb 7 15:43:46 2014 -0500

    Specs related to Paige::Rails::COntrollerHelpers#paige

commit be278928474ae6f81607c971aed733a2463baab6
Author: Daniel Pehrson <dpehrson@qurve.com>
Date:   Fri Feb 7 15:25:18 2014 -0500

    Specs for hash-related functionality

commit f15ddd4defc36b413b2cd6676ee56e17f1f056e2
Author: Daniel Pehrson <dpehrson@qurve.com>
Date:   Fri Feb 7 13:58:08 2014 -0500

    Proof-of-concept for serializing/unserializing container data to and from hashes which can be used by the controller helper to temporarily store that data in the flash across redirects.
Merge branch 'gtm-datalayer'
Bump to version 0.6.0