[Pulp-list] Agent Heartbeat

[Jeff Ortel]

All,

As part of fixing https://bugzilla.redhat.com/show_bug.cgi?id=632277, I update the pulp 
agent to publish heartbeats on the bus.  The pulp server collects statistics on consumer 
(agent) availability.  This information is available through the REST API:

    /services/agent/status/

The heartbeat interval is configured in client.conf.  So, if you're running out of dev-env 
and not symlinking this, you will need to add:

[client]
heartbeat=10

Or, whatever interval makes sense to you.

In either case, you'll need to restart goferd.

The CLI takes the agent status into consideration when doing operations that involve 
running commands on the agent.  Namely, package install.  If the agent appears to be 
unavailable, the user is advised and given choices.  The agent status is also visible when 
running 'consumer info|list'.

I also updated the waiting graphics to match what is shown during a repo foreground sync 
(or at least similar).

-jeff