bump composer packages
remove fosrestbundle

Will reaadd willdurand/negotiation as needed further down. As that seems to be the only
part we will still be using (it seems we've already fully replaced the bundle for all other
matters).
update to newest symfony 2.5
use new request_stack facility
Merge branch 'feature/update-symfony' into develop
Merge branch 'develop' into feature/i18n

Conflicts:
	composer.lock