virt-sandbox: New virt-test subtest for virt-sandbox and virt-sandbox-service command (lxc under the hood)

This only "works" on F19+ boxes....and there are a lot of underlying bugs.  Though the tests do all pass, when virt-sandbox is working :)

Essentially these tests are geared toward building up many combinations of combinations of command-line-option driven tests.  There's one sample/default test included which runs the date command in several different ways.  Writing new tests is largely class-creation driven, by subclassing an aggregation manager and/or sandbox classes.  Both are fed by params in a standard but extensible way, with all the built-in tooling geared toward performing operations on sandbox lists-of-lists.

I had to add a LOT of <code>run, bootstrap, standalone</code> special-handling since this sub-test's config. requirements are sooo simple.  It was much easier to just remove all the VM/OS/Shared stuff than to make it parse many many many irrelevant keys for this harness.  Anyway, I tried to get these decisions in the right places, but there were a LOT of places :S  If there's a better way to have done this, I'm all ears.