(PUP-3274) Remove acceptance setup step to set parser

The old parser/evaluator have been removed, and there is no longer a
:parser setting and switch. The acceptance setup step which allowed the
setting of 'parser' in puppet.conf prior to a run is therefore obselete
and now being removed.
(maint) Do not add delivery domain to generated hosts

...unless it is missing. Earlier versions of Beaker, I believe, provided
a host name that was not an fqdn, and when our Rakefile was creating a
config to allow Beaker to be re-run against preserved hosts, it would
add the delivery domain. Now, hostnames are being found fully qualified
in the logs, and we need to only add the domain if the hostname is not
qualified.

This commit also refactors the code that releases vms to make use of the
internal vmpooler rather than relying on Beaker::VcloudPooled, whose
interface may change.
Merge pull request #3333 from jpartlow/issue/master/pup-3274-remove-set-parser-acceptance-step

(PUP-3274) Issue/master/pup 3274 remove set parser acceptance step
(PUP-1362) (PUP-1775) remove :python command

No longer needed after removal of yumhelper.py
(PUP-1362) (PUP-1775) map yumhelper.py's -e & -d flags to yum

The -e & -d flags to yumhelper.py had different semantics than yum's -d & -e
flags.  The yum equivalent option flags are --enablerepo and --disablerepo.