Cleanup/refactor new dpkg selections support

This builds on the code merged in c2a304c, correcting some style-related
issues, reducing the number of times that get_selections() needs to be
called within set_selections(), and raising the proper exceptions when
invalid input is specified.
Add level passing support to the temporary logging handler.
The null logging handler should only output warning level messages.
Don't feed logging handler messages which they're not supposed to handle.
Allow the Logstash ZMQ high water mark to be configurable.
Fix the salt CLI tools version check test case
Merge pull request #7056 from s0undt3ch/develop

Fix unwanted TRACE level messages
Merge pull request #7054 from terminalmage/dpkg-selections-refactor

Cleanup/refactor new dpkg selections support
update heredoc to deploy fresh when the master is updated
Fix path to salt version tag
cleanly handle the local key in the ret
Check for each service status individually

In case they self report out of order
Adapt test case to Suse based distributions.
Make use of the `requires_system_grains` decorator
Merge pull request #7058 from UtahDave/fix_supervisord_test

Check for each service status individually
Suse based distributions(at least) complain when a `username` or `group` starts with digits.
Merge pull request #7060 from s0undt3ch/develop

Suse user tests fixes
Non zero exit codes should be considered errors.
inherit object
improve memory management in ssh contexts