Use _ prefix instead of _real suffix on variables

On the whole, the style in manifests for variables that have been
modified in a local scope and saved to a new variable name have shifted
from using `$foo` -> `$foo_real` to using `$foo` -> `$_foo` due to the
shortness of the form and semantic implications that `$_*` is not
neccessarily human-friendly.
Merge pull request #257 from laurenrother/PR_reference_updates

Update instructions for installing a module from a release tarball
Docs updates for 3.4.0 final

Just moving the references, since they're unchanged, and adding a note about PUP-1015.
Moved PE user guide link on docs home page so it's easier to find.
Copyedit a stray sentence in modules_installing
Changes for 2.84 and 3.11
Copy edits to 3.1.1 appendix and what's new.
( DOC-9 ) Fix ordering of units for report prune rake task

This patch changes the ordering of the units for the report pruning rake task from random to descending chronologically. This makes the docs easier to read and understand.
Merge pull request #258 from llowder/fix_for_doc_9

( DOC-9 ) Fix ordering of units for report prune rake task
Copy edited
Merge branch 'master' of github.com:puppetlabs/puppet-docs
Copy edited
Guts: Stop tracking Gemfile.lock

This file is designed for use with a Bundler workflow we don't really use, so it
ends up being unproductive noise in our SCM. We should just gitignore it and
allow every user to have their own copy.
Copy edited
Merge branch 'master' of github.com:puppetlabs/puppet-docs
Copy edited
Fix missing protocol in URI for JIRA
Change protocol from HTTP to HTTPS to make the installation more secure
Updating What's New and Appendix for 3.1.1/2.8.4 releases

Merge branch 'pe311-284'
Fixes a couple typos in Appendix and What's New.