If a requested fact isn't found in the same location as its name, we want to
load all of the facts to find it. However, to simplify that, we were previously
just preloading all the facts every time. Because requesting a fact now
implicitly loads all facts if necessary, we can rely on that, providing results
much more quickly in the case where facts do match their filenames.

Reviewed-By: Jacob Helwig <jacob@puppetlabs.com>

With the previous behavior, any fact which depended on another fact in a file
not matching its name would fail to properly load the required fact, resulting
in missing, incorrect, or inconsistent values.

For instance, the operatingsystem fact depends on the lsbdistid fact found in
lsb.rb. The first time the operatingsystem fact is requested, it requires
lsb.rb, and so the required fact is loaded first. But if Facter is subsequently
cleared and the operatingsystem fact requested again, the require will not
occur, and the fact will not be automatically loaded because it doesn't match
its filename.

Now if a fact is requested and can't be found, we will attempt to load all the
facts to find it. Such an approach appears heavy-handed, but in the case where
we want a particular fact, this is the only way to make sure we've found it. In
the case where we eventually want other facts, we are conveniently eagerly
loading them.

Paired-With: Jacob Helwig <jacob@puppetlabs.com>

* master:
  Update CHANGELOG for 1.5.9
  Updated CHANGELOG for 1.5.9rc6
  Removed inappropriately uncredited Ohai method from ec2 fact
  Add facter test for ticket 7039
  downcase arp output so that the ec2 arp is matched
  (#7039) Pre-load all facts when requesting a single fact

* ticket/next/6728-facter_improperly_detects_openvzve_on_cloudlinux_systems:
  (#6728) Facter improperly detects openvzve on CloudLinux systems
  (#6883) Update Facter install.rb to be slightly more informative.

Calling #to_s on an Array such as ["foo"] in Ruby 1.9 will result in
the string '["foo"]', instead of stringifying the element in the array
which would have given the expected result of "foo".  Since the
element of the array we're dealing with is already a string, we can
just grab it out of the array by using #first.

Paired-with: Josh Cooper <josh@puppetlabs.com>

CentOS 5.4 arp gives the arp output as uppercase; downcase it so
we're ensured a match

Since multiple facts can be defined in a single file and we have no
way of knowing which "additional" facts are defined in which files, we
pre-load all facts when we're looking for specific one.

Paired-with: Max Martin <max@puppetlabs.com>

Make the openvz check for more than just the vz directory to be sure it's
OpenVZ.

Update the OpenVZ fact to be slightly more resilient in it's checking of
OpenVZ, so it doesn't clash with CloudLinux's LVE container system.