Add swiftpolicy middleware project on StackForge

The SwiftPolicy Middleware for OpenStack Swift allows
to use a JSON policy file to handle swift authorizations.

The project is currently available on github:
https://github.com/cloudwatt/swiftpolicy

Change-Id: I6a3a7b0a4da35d0eb047face592aad7bfee2655c
Merge "Add swiftpolicy middleware project on StackForge"