pep8 for run_memory

Signed-off-by: James Molet <jmolet@redhat.com>
subtests...run_memory: Update test

* Change ``print`` statements into ``logdebug``
* Prefix logged & exception messages with sub-subtest name
* Removed logging of successful result details (still logs negative)
* Interpret cgroup value 9223372036854775807 as
  equivilent to 0 for test purposes
* Use ``os.path`` for cgroup path formation
* Updated docs

Signed-off-by: Chris Evich <cevich@redhat.com>
config_defaults/default:  Comment fix

The ``remove_after_test`` option was incorrectly
documented as being deprecated, moved it and
added it's own comment.

Signed-off-by: Chris Evich <cevich@redhat.com>
Merge pull request #177 from cevich/run_memory

Run memory