Merge pyfarm.core.sysinfo into pyfarm.agent

This commit contains all previous history for `pyfarm.core.sysinfo` as well as any fixes to make the merge possible.  The only changes introduced by this merge are a couple of minor items:

* removal of a test where we were testing the output from a logging statement
* a couple of import reorders for PEP8
* updates to the logger name to use the agent's logger

Other than the above there are not any functional differences between the code in this merge and the original `pyfarm.core.sysinfo`