Symfony 2.5 support

Tested this with symfony 2.5 and it's working fine. 

I had to do the same in the bundles.
codeconsortium/ccdn-user-admin-bundle
codeconsortium/ccdn-component-bb-code-bundle
codeconsortium/ccdn-component-common-bundle
codeconsortium/ccdn-message-bundle

but no problems encountered so far