Nicira neutron plugin integration bugfixes

  l23network/lib/puppet/provider/l2_ovs_nicira/ovs.rb
    - correct argument order for ovs-vsctl set-ssl
    - connector type mapping
  neutron/manifests/agents/dhcp.pp
    - fixed service requirements for dhcp agent for non-HA
  neutron/manifests/plugins/nicira.pp
    - added nicira's package and service
Change-Id: Id8299a6007729de4babc7536e9f26e551d4420a5