(docs) Edit header of metaparameter reference

The language here was kind of ancient, and this commit updates it.
("Instances" -> "resources", among other things.)
(maint) Consolidate case statement in /pson/pure/generator.rb for the Float module.

Prior to this commit, the to_pson method for the Float module contained
unnecessary duplicated code.  This commit removes the duplication by
consolidating the case statements into a single if statement.
(doc) Add some missing options to apply/agent/doc/queue usage messages
(PUP-2506) Trivial Ruby bug in Puppet::Resource::Ral

Prior to this commit, a bug is triggered when the Puppet::Error string
is interpolated. The #type method was called recursively and failed with
an ArgumentError: wrong number of arguments (0 for 1).

This commit fixes the bug by changing which variable is interpolated in
the string.  It also adds a spec test for this case.
(maint) Update docs badge in README

Update the URL of the docs badge to include it from
inch-ci.org instead of inch-pages.github.io (the former
being the successor of the Inch Pages project).
Merge pull request #2733 from rrrene/patch-2

Update docs badge
(PUP-2364) Use the the puppet config vardir setting

instead of the beaker variable puppetvardir.  This change, while
pleasing in and of itself, was needed for testing on AIX.  The vardir
used there by puppet is different, and Beaker does not track a separate
set of defaults for AIX.
Merge branch 'pup_2364_spike_vars' into stable

* pup_2364_spike_vars:
  (PUP-2364) Use the the puppet config vardir setting
(PUP-2650) Add :array setting type
Merge pull request #2706 from nfagerlund/docs_metaparam_header

(docs) Edit header of metaparameter reference
(doc) Recommend git checkout -b in CONTRIBUTING.md

git checkout -b is equal to git branch && git checkout.

Closes #2737.
Merge pull request #2718 from scop/usage-messages

(doc) Add some missing options to apply/agent/doc/queue usage messages
Merge pull request #2719 from razalas/issue/master/pup-2506-trivial-ruby-bug-in-puppet-resource-ral

(PUP-2506) Error when evaluating #type in Puppet::Error message interpolation for Puppet::Resource::Ral
Merge pull request #2717 from razalas/fix/master/remove_code_duplication

(maint) Consolidate case statement in /pson/pure/generator.rb for the Fl...
(PUP-2650) Add disable_warnings setting

This commit adds a new setting that allows users to disable different
classes of warnings. Right now the only supported type of warning that
can be disabled is 'deprecations'.
(PUP-2650) Defer deprecation warnings until we can read disable_warnings

The difficulty with using the value of the disable_warnings setting to
adjust deprecation_warnings issued for other configuration settings is
that we need settings to finish initialization first.  Otherwise
deprecation_warnings become dependent on the order of setting
initialization.  To account for this, I added a deprecated attribute to
base_setting, allowing us to mark any setting as deprecated completely
or allowed_on_commandline.  And the code in settings to issue
deprecations now tracks deprecated settings as they are configured, and
then issues the deprecations after the application is initialized.
Merge branch 'pull-2740' into stable
Merge branch 'stable'

Conflicts:
	lib/puppet/defaults.rb
Merge branch 'master' into puppet-4