Remove useless import
use willdurand/negotiation
lets allow 1.0.* for now

as the lib is still a bit fresh rather not depend on ~1.0
Merge pull request #511 from FriendsOfSymfony/use_negotiator_lib

use willdurand/negotiation
Merge pull request #509 from armetiz/patch-1

Remove useless import
Issue in configuration tree, the validation for the parameter `param_fetch_listener` is set
in the `cache_dir` parameter.

Issue #513
Add XML definition in util.xml

Added missing XML definition in util.xml file.
Merge pull request #515 from aferrandini/patch-1

Add XML definition in util.xml
Merge pull request #514 from aferrandini/master

Configuration tree issue