Cleanup for #13160

This commit makes the changes from #13160 conform to the Salt way by
kreturning booleans for enable/disable. In addition, it makes the
following changes:

1. Adds versionadded directives

2. Fixes leaked file handles by using with statements (and
   salt.utils.fopen).

3. Raises a CommandExecutionError in ares where the failure of a
   function reaches an error case.
correct erroneous os.kill() statement
add missing reference to error message
Merge pull request #7 from mfournier/os.kill-fix

fix mistake mentioned in #13162
Merge branch 'puppet-housekeeping' of https://github.com/terminalmage/salt into terminalmage-puppet-housekeeping

Conflicts:
	salt/modules/puppet.py
Merge branch 'terminalmage-puppet-housekeeping' into develop