Pulp

This story is designed to create a new section in the docs describing how to setup and use the lazy sync with Pulp. At a minimum it will need the following sections (all on one page):

0. Overview. This should include a feature description of active and passive mode along with a good diagram.
1. Installation. Covers the software installation of the pulp-streamer and squid.
2. Configuration of settings in server.conf, httpd directive uncommenting in the main Pulp httpd.conf, and squid config.
3. API usage: how to enable a repo for 'lazy active' or 'lazy passive' using the importer config attribute named 'lazy_sync'.
4. pulp-admin Usage: how to configure a repo to do a lazy sync along with a simple zoo repo example perhaps.

These docs should note that in "active" lazy mode, the asynchronous task that downloads content can be monitored as a spawned task on the sync operation.