Squashed issue's commits
SONATA-260 - Added twig status class extension

Removed service that should be defined in ecommerce bundle

Removed unused variable

SONATA-260 - Added unit tests

Coding standards fix
SONATA-265 - Added doc related to SONATA-260 (twig status helper)

SONATA-265 - Added doc related to SONATA-260 (twig status helper)

SONATA-265 - Added doc related to SONATA-260 (twig status helper)

Typo

Typo
Added prefix to service name
Lowered twig-bridge required version to be Sf2.2 compliant
Merge pull request #6 from xavismeh/master

Added twig status class extension