Docker: Add environment check job between tests

* Generalizes output.OutputGoodBase into environment.AllGood
* Fixes up output.OutputGoodBase to use new general interface
* Preserves all existing interfaces
* Added standalone executable helper script that is able
  to send default configuration options through and execute
  any executable placed under the 'envchecks' subdirectory.
* Added envchecks/README explaining the (simple) requirements
* Updated control file to call run_envchecks.py script at the
  beginning and in-between every test.  Any negative results
  are reported, but non-fatal.

Signed-off-by: Chris Evich <cevich@redhat.com>