rpcdaemon: allow specification of enabled plugins

closes rcbops/chef-cookbooks/issues/944
Fix for Issue 941

Process is to stamp the DB and then make a revision note indicating this is an RCBOPS deployment which is then used to ensure that the DB is NOT stamped on subsequent chef runs.

This commit adds new node attr hash to the ["neutron"]["db"]["stamp"]

The DB stamp will only be attempted when the RCBOPS deployment $REVISION
is not found in the neutron db history.

This also fixes some syntax issues we had in addition to making the recipe more legible.

Issue:
rcbops/chef-cookbooks#941
Merge pull request #139 from claco/issue-941

Merged automatically by jenkins after successful build test
Merge pull request #135 from cbuben/issue-944

Merged automatically by jenkins after successful build test
Reintroduce l3 router/gateway settings in l3 agent

This partially reverts commits f37dc6e037450a1c6dd0d20e05f99185efa6124f, e969a6f69eefc722c6fcd5d41ddbd6c30d36ce5b

Issue rcbops/chef-cookbooks#933
Merge pull request #138 from claco/issue-933

Merged automatically by jenkins after successful build test
Make api_workers configurable

- Add api_workers attribute and neutron.conf template variable

Issue rcbops/chef-cookbooks#935
Merge pull request #140 from claco/issue-935

Merged automatically by jenkins after successful build test