(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-2745) Skip dependencies with malformed dependencies.

Prior to this commit if we encountered a dependent candidate module with a
malformed dependency, we would just ignore the malformed dependency.
This commit changes that behavior to ignore the entire dependent candidate as
an invalid module, this preventing the installation of a module with unknown
dependencies.
(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.
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
Merge pull request #2980 from highb/fix/master/pup-2745_skip_module

(PUP-2745) Skip dependencies with malformed dependencies.
(PUP-2040) .pmtignore and .gitignore for build

Prior to this commit there was no way for a module developer to specify files
that they want to ignore when building/packaging their module.

This commit adds the ability to specify files to ignore in a .pmtignore file,
located in the project root and using the same syntax as .gitignore, or if that
is not present, reading the .gitignore file and using that.

This commit also adds pathspec as a vendored gem. (PE-5574)
(PUP-2040) .pmtignore spec tests

Adding spec tests to cover build when .pmtignore/.gitignore files are present/absent