Currently, server_job parses a whole bunch of arguments to autoserv and provides these to a server test control file via the namespace.

From there, the control file pulls out some of the data and manually passes it in to the server test's run_once method.

This is not extensible.
In preparation to making HostInfo available to the tests, we will create a TestArguments object
- This is created by the server_job,
- It is passed in to the control file through the namespace (and consolidates a bunch of globals currently passed in through the namespace)
- It is also passed in automagically to the server side tests' run_once method.


In particular,
- This object will contain the Host object that server side control files currently create in an ad-hoc method and then pass in to the tests.
- This will contain the afe_host object currently passed in via the machines dict.
- In the future, it will contain the HostInfoStore, which will replace the afe_host object passed in via the machines dict.