Split DNS database handling into its own recipe.

Make the other recipes attribute-driven while we are at it.
The method that the DNS database role is using to keep the database updated
is racy right now, that raciness will be resolved by updating how we
manage node role runs.
Merge pull request #61 from VictorLowther/pull-req-master-763d805705b2c4a304d3ae9606be913bd4cca504

https://github.com/crowbar/barclamp-dns/pull/61

Merged by devtool for cloudedge
Make DNS barclamp use the new Run infrastructure.
Merge pull request #63 from VictorLowther/pull-req-master-b8895885003093f140e37ed4f5efc36a05f38852

https://github.com/crowbar/barclamp-dns/pull/63

Merged by devtool for cloudedge
Make dns-client an implicit role.
Add server flag to the dns-server role.
Merge pull request #64 from VictorLowther/pull-req-master-adf59d76e7c4525496432dae4e35f36b067b56c2

https://github.com/crowbar/barclamp-dns/pull/64

Merged by devtool for cloudedge
Clean up rerun_my_noderoles a bit.
Merge pull request #66 from VictorLowther/pull-req-master-7e4d4af3d6449b9d69d65e99a3e4e9c72ba47979

https://github.com/crowbar/barclamp-dns/pull/66

Merged by devtool for cloudedge