Add ospurge project.

ospurge is a client side script allowing an OpenStack administrator to
cleanup any project, by deleting all of its resources prior to
deleting the project itself.

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

Change-Id: If56d6e7be2972e27c08343b1b0c3b36aba068e21
Merge "Add ospurge project."