add each role for each network main component

In typical openstack configuration, there may be 3 types nodes:
controller node, network node, and compute node. From the network
point, it's always supposed that: the Quantum Server is on the
controller node; and the L2 agent, DHCP agent and L3 agent are on
the network node; the L2 agent are on the compute node. We need the
each role for each OpenStack network main component. This will make
the configuration more flexible. So I add them here.

Change-Id: Ida4826c6dfe770b58790d75561bea42e9584ca89
Closes-Bug: #1240509
Adding forwarded_ports for Vagrantfile

 * forwarding dashboard-ssl
 * forwarding nova-api
 * Converted vagrant enviroment to ruby format

Change-Id: Ic406d93ea8ab8933ce9d5dc90bcd6410c847c9f4
Merge "add each role for each network main component"
Merge "Adding forwarded_ports for Vagrantfile"
open port 4000 for Chef-Zero access

Change-Id: Ica8b0aadf6f17039399317470392650ac176847c
add metadata-agent network role

...and the accompanied entries in role[os-network] and
infrastructure.yml.

It seems like this was forgotten in the earlier commit,
323843237c10e5a8ebf245bc23ff159f9fe311a5, at least the OVS plugin of
Neutron needs this agent.

Change-Id: I69c0543597624497c9a40e731e355b8f64d5b3fb
Merge "open port 4000 for Chef-Zero access"
starting the instructions for the Hong Kong workshop