(PUP-2914) Add rgen 0.7.0 to vendored libraries

This commit adds the rgen 0.7.0 library by placing it in the vendor lib
that is needed for development on the new parser.
(PUP-2914) Remove rgen 0.7.0 dependency

The library rgen was an unnecessary dependency since it was
vendored. This commit removes unnecessary dependency.
(doc) Add Puppet Specific Documentation

Vendored libraries had no way for us to tell where they had come from or
what version the library was at.
This commit adds `PUPPET_README.md` files to each of our vendored
libraries to give us more information about where they came from.
(PUP-2817) Fix zone properties so that nil is not passed through

Before this patch, when `insync?` was called on the zone properties ip,
dataset and inherit with value nil (happens the first time when the properties
are not present), `true` was returned, which resulted in them not being set
until the values were actually queried, which happened after the installation
of zone. Unfortunately, the inherit property can only be set before
installation.

This patch removes the spurious check for `nil`, which always returned `true`,
and instead handles it similar to when `:absent` is used.
(PUP-406) Deprecate stringify_ facts option

The `stringify_facts` option is going to be removed in Puppet 4.0 and we
need to let users know about deprecated features.

This commit adds in a deprecation message in the stringify_facts
description.
(PUP-586) Deprecate Instrumentation System

The instrumentation system is being removed in Puppet 4.0.

This commit is for adding a deprecation message on the subcommands for
users to migrate off of it before it is finally deleted.
(maint) Fix up regex in indirector rest spec 404 tests

Seeing sporadic failures on 1.8.7 with these two tests, probably related
to order of parameter keys not being guaranteed.  This patch loosens the
regex on these two tests slightly so that it the keys can be in any
order.

With Britt Gresham <britt@puppetlabs.com>
Merge remote-tracking branch 'upstream/pr/2995'

* upstream/pr/2995:
  (doc) Add Puppet Specific Documentation
  (PUP-2914) Remove rgen 0.7.0 dependency
  (PUP-2914) Add rgen 0.7.0 to vendored libraries
Merge pull request #3000 from demophoon/deprecation/master/deprecate-stringify-fact-default

(PUP-406) Deprecate stringify_ facts option
Merge pull request #2998 from demophoon/deprecation/master/deprecate-instrumentation-system

(PUP-586) Deprecate Instrumentation System
Merge pull request #2973 from vrthra/fix/pup-2817/zones

(PUP-2817) Fix zone properties so that nil is not passed through