Update webapi doc with link and console

http://docs.openstack.org/developer/ironic/webapi/v1.html is updated
as follows:
- changes the path descriptor of NodeStates to use '(node_uuid)' instead
  of '<uuid>' to be consistent with other paths
- adds [GET/PUT] /v1/nodes/(node_uuid)/states/console to show how to
  access the node's console
- fixes the "Links" section so that Link information is shown

Change-Id: I9d4a32550b81bb5ccf2fa23d8b591d8a945c04cc
Merge "Update webapi doc with link and console"