Precising configuration of DNS to deploy CF release, and IP semantics.

micro bosh should have recursor configured so that DEA are able to resolve DNS entries their app will require.
CF deployment should not list dns entries into their cloud properties and rather rely on the bosh powerDNS.
Precised semantics of reserved and static section in networks

Contributes to fixing https://github.com/cloudfoundry/cf-docs/issues/271