Added Confguration to support OpenCloud based CDN's based on OpenStack, and also Rackspace.
Changed id to key in gaufrette.xml
Fixed app/AppKernel Notes in installation.rst
Added opencloud lib as suggested library to composer.json.
Fixed Composer.json spacing issue for suggested dependency.
Fixed configuration.php, fixed installation.rst and composer.json per rande's notes.
Fixed installation.rst per rande's Notes.
Merge pull request #411 from cdwlighting/master

Added Configuration support for Rackspace and other OpenStack Vendors.
Fix validation to use interface
Fix translation
Merge branch 'sonata/master'