(PUP-1362) (PUP-1775) Use yum check-updates for latest yum packages

Early versions of the yum package provider used `yum list available` to
determine the latest version of packages that were `ensure => latest`.
However the versions of yum available around that time changed the
output formatting of yum, which meant that the parsing code would break
on a regular basis (#836).

Commit 8722e439 resolved this by using the yum python bindings to
interact with yum. This required shipping a python helper script to
provide the interface between Puppet and the python libraries. However
this opened up a host of other issues ranging from what version of
Python is symlinked to '/usr/bin/python', how the yum database is
locked, and so on (PUP-1362, #11380, #16623). In addition changes to
yumhelper.py were very hard to test or reason about since it doesn't
neatly plug into our existing tests.

This commit removes yumhelper.py and replaces the update checks by
calling `yum check-update`. The output format of this command has not
changed since CentOS 4 and works all the way up to RedHat 7 so we should
be able to rely on this for a while.
(docs) Note that the path setting only works in main section of puppet.conf

See PUP-3023 for more info.
(PUP-3227) Address man page ownship conflicts

Prior to this commit, upgrading from puppet=2.7.23-1~deb7u3 and
puppetmaster=2.7.23-1~deb7u3 to puppet=3.7.0.29-1puppetlabs1 and
puppetmaster=3.7.0.29-1puppetlabs1 fails. I believe this problem is due
to how Debian chose to package puppet-common, which owns
`/usr/share/man/man8/puppet-master.8.gz`.

This commit adds in a `Conflicts:` to the puppetmaster and
puppetmaster-common packages to make sure that we can successfully
upgrade from these older package versions. However, if a user has
puppetmaster and puppet older than 3.3.0 installed on a machine, and
only upgrades puppetmaster, this will uninstall the puppet package from
the system.
(maint) Remove GC bug workaround for Ruby < 1.8.7

Commit bd5dc649 added a workaround for a Ruby GC bug that was present in
1.8.5, 1.8.6, and partially fixed but still residual in 1.8.7. Since
we're dropping Ruby 1.8 support entirely we can now remove the
workarounds.
(PUP-1106) Unschedule refreshes on skipped resources

If a given resource is being skipped (e.g. has failed dependencies, is
unscheduled, untagged, etc) that resource should not trigger any
additional behavior. However a resource could be skipped and still have
events trigger behavior. This commit changes the event processing logic
to only process events for resources that should be applied and dequeues
events on resources that should not be applied.
(maint) Use correct data type when unscheduling events

Commit 9d59f204 added the ability to dequeue events on a given resource,
but it did so by setting the value of the target callbacks to an empty
hash. However the value of target callbacks is an array, so if events
were re-queued for a given resource we would get an error like so:

    {}.concat(%w{one two three})
    NoMethodError: undefined method `concat' for {}:Hash

Currently we can't requeue events after dequeuing events, but if this
changes then this code is very incorrect.

This commit fixes the event reset to behave as expected.
(PUP-3322) Add debugging to appdmg provider

I was trying to install Scratch[1] using boxen[2]. The appdmg isn’t in
the expected format, so this failed. I had to poke around a bit to
understand why that was happening. This change captures that knowledge.

[1] http://scratch.mit.edu/scratch_1.4/
[2] https://boxen.github.com/
(PUP-3355) Remove PSON document_type

This commit removes the encapsulation in the PSON serialization format.
Puppet only did this when using PSON on certain endpoints, other formats
like YAML or MsgPack never did this.

This is backwards compatible with older Puppet versions as they throw
away the info if it is there. But it is backwards incompatible for other
consumers of the PSON APIs.
(PUP-3355) Remove Puppet::Util::Pson

Remove the now unused Puppet::Util::Pson class.
PUP-3366 Fix issues with string/enum type assignable calculations

There were errors in the calculation of string/enum calculation.
Basically Enum == String, if String is size constrained then
Enum < String. This fixes this calculation.

There were no tests for this, they are now added.
(PUP-3244) ENC ignores missing directory environments

When using an ENC, if an environment that didn't exist was defined for a
node puppet would place the node into the production environment instead
of raising an error to alert the user that the environment that had been
requested did not exist.

This commit changes the behaviour when an environment is defined in an
ENC but does not actually exist. Instead of placing the node into the
production environment a Puppet::Environments::EnvironmentNotFound error
is raised.
(PUP-3365) Change 3x deep map of undef to only do surface map

This changes the mapping of arguments to 3x function calls to not
map undef to empty strings except at the surface level. Other mappings
are still done as they are required for frozen strings, and values
having a type that is not supported by the 3x functions.
(PUP-3308) Remove deprecation warning about cron purge change

This commit removes deprecation warnings for the :purge attribute
of the cron resource. Previously, when 'purge' was set to true
for unmanaged cron resources, Puppet would fire off a warning
about the 'purge' option becoming more aggressive in future versions.

This update is part of the code removal effort for Puppet 4.
(PUP-3244) Acceptance Tests for Nonexistent Environments

Added acceptance tests to test if an error is raised if an ENC specifies
a nonexistent environment for a node.
(maint) Correct Certificate Factory documentation

The existing certificate factory documentation incorrectly indicated
that it was responsible for actually signing certificates, which it is
not. In addition it specified a parameter as a raw
OpenSSL::X509::Request which it is actually the wrapped
Puppet::SSL::CertificateRequest.
(PUP-2998): Make log_level settable in puppet.conf

Added a call hook to the `log_level` setting so that this setting can be
defined in `puppet.conf` in addtion to being passed as a command line flag.
(PUP-3244) Validate Environment Before Setting

Before this commit the environment validation was happening for the Exec
terminus instead of on the node object itself. This fix should help all
node objects from having invalid environments when its environment is
set using `Puppet::Node#environment=`.
(PUP-3363) Make transformation of unparenthesized calls handle errors

This fixes problems when a user enters commas where they are not
supposed to be. As a result, an expression will be parsed as being an
argument list for an unparenthesized function call. The transformation
logic for such calls did not take one case into account; a non call
followed by an argument list. e.g:

$a = 1,10

Which resulted in a strange AST model (a literal list with an assignment
and a 10).

This commit adds error checking and raising of an exception in the
transformation which is caught by parser_support and formatted into an
error - either about an illegal comma (when the LHS cannot possibly be
a call at all (as in the above exampel), or a more elaborate
message about that what could be a function call requires parentheses.

In order to enable positioning of the error message on the first comma
in the argumet list, the comma tokens were required in the expression
list fed to the transformer. Subsequently these tokens must be filtered
out by the transformation, and passed on in the raised exception (since
the receiver would otherwise not know which token that caused the
problem (it is nested inside the stucture it passes on to be
transformed).

Unparenthesized function calls are a very bad idea...
(PUP-3366) Correct comparisson of Enum > Enum[a]

Comparissons involving an unparentesized Enum were not correct
because an iteration with all? returns true if the set being
enumerated is empty.

This modifies the logic, and adds missing tests.
(PUP-3299) Remove deprecated Puppet::Util::CommandLine methods

This commit removes the deprecated class and instance methods
`available_subcommands` from the Puppet::Util::CommandLine class.
They are replaced by `Puppet::Application.available_application_names`.

This commit is part of the code removal effort for Puppet 4.