Deprecate quota_injected_file_path_bytes (update for Juno)

* Deprecate [DEFAULT]/quota_injected_file_path_bytes in favor of
  [DEFAULT] quota_injected_file_path_length.
* Remove quota_max_injected_file_path_bytes parameter.

Use new parameters for Juno like it's documented here:
http://docs.openstack.org/trunk/config-reference/content/nova-conf-changes-master.html

Change-Id: Ia408de8fa980b37e6d46dece8d90a83f2083df8a
Partial-Bug: #1391099