Enable conversion for composite attribute items

Bug 1207881

Enable 'dict validators' to convert composite attributes' items
using a 'convert_to' specification in a way similar to first-level
API attributes.
This is needed in order to ensure boolean sub-attributes are
properly handled.

Change-Id: I7f466befaa88112cf7e9b77d854ac292b2af638f
Firewall as a Service (FWaaS) Iptables Driver

blueprint quantum-fwaas-iptables-driver

This is IPTables Driver for "Firewall As A
Service" feature.

This implements
- Fwaas rules are mapped to IPTables
- The rules are installed in the network
  namespace of quantum-routers

Change-Id: I157182f2c86fbcf8c141b9ad3cfc71168153ebf8
Merge "Firewall as a Service (FWaaS) Iptables Driver"
Merge "Enable conversion for composite attribute items"