Fix to Virtual Machine detection on Darwin

[keeleysam]

Using SPDisplaysDataType causes lagging issues on pre-2013 Macs, so use
other sources from system_profiler which do not have the issue and are
also more reliable.

[glarizza]

I'm positive the Facter team will review your pull request, but just a heads up - this looks like it would cause some build failures ( https://travis-ci.org/puppetlabs/facter/jobs/17210641 ) in the spec tests, specifically these tests --> https://github.com/puppetlabs/facter/blob/master/spec/unit/virtual_spec.rb#L50-L74

If you feel comfortable, can you take a look at submitting a commit to update the tests in line with your pull request?

[keeleysam]

Thanks for the heads-up. I did actually update the tests, just forgot to git add them! Doing that now.

[ahpook]

We are in kind of a weird place with regard to facter pulls right now because we're in 2.0 RC and do not have another 1.7.x release planned. That said we'd like to get this in a release, especially now that tests are passing. @adrienthebo can you look at this in the next PR triage and see if it can get into both pe_facter and future oss releases?

[adrienthebo]

@glarizza I'm not an OSX expert, are you okay with this approach for getting this data? If so we can merge it.

[adrienthebo]

The previous implementation of this had some limited case insensitivity, does that need to be preserved?

[keeleysam]

I have check all versions of Fusion, VMware Fusion/ESXi, and Parallels, and it they all show the same, it does not need to be case insensitive.

[adrienthebo]

This looks good, but before we merge this it would be good to do a little bit of bookkeeping. I can't recall if I already asked for this but it would be good to have a JIRA issue associated with this issue. In addition the commits should be squashed into a single commit, and the commit message should be updated to match the format in https://github.com/puppetlabs/facter/blob/master/CONTRIBUTING.md#making-changes . These changes make it easier to understand what was done here in case we need to review this later. Thanks

[ahpook]

@adrienthebo https://tickets.puppetlabs.com/browse/FACT-231

[adrienthebo]

Merged into facter-2 in f221887; this should be released in 2.1.0. Thanks for the contribution and sorry about the delay!