This test runs only on Ubuntu machines and will reproduce the problem with these steps:

  * load Facter
  * request the operatingsystem fact
  * clear Facter
  * request the operatingsystem fact and verify it is still correct

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

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>

* next: (32 commits)
  (#7507) Fix 1.9.2 test failure
  Removed inappropriately uncredited Ohai method from ec2 fact
  (#6614) Update ipaddress6 fact to work with Ruby 1.9
  (#6612) Changed uptime spec to be endian agnostic
  (#6728) Facter improperly detects openvzve on CloudLinux systems
  (#5135) Fix faulty logic in physicalprocessorcount
  Ensures that ARP facts are returned only on EC2 hosts
  Fixed #6974 - Moved to Apache 2.0 license
  refactor the mechanism for allowing for resolution ordering to be influenced
  (#6740) facter doesn't always respect facts in environment variables
  Partial fix for #6971 - Fix for virtual tests
  (#2714) Fixed faulty test
  (#2714) Added timeout to prtdiag resulution
  (#5135) Refactored physicalprocessorcount
  Re-factor. Do not use pure-Ruby file reading against "/proc/cpuinfo" and possibly any entry under "/sys" from the sysfs file system.
  Fix. Using sysfs file system entries to count the number of physical CPUs. Fall-back to "/proc/cpuinfo" included for backward-compatibility with legacy systems.
  (#3856) Add virtualbox detection via lspci (graphics card), dmidecode, and prtdiag for Solaris and corresponding tests. Darwin case is not handled yet.
  (#6883) Update Facter install.rb to be slightly more informative.
  (#5394) Document each Facter fact.
  (#6862) Add a default subject for the mail_patches rake task
  ...

* 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/7507-ruby19_fix:
  (#7507) Fix 1.9.2 test failure

Dir.glob returns an array, but a test was stubbing it to return a
string.  In Ruby 1.8.7 if you call enumerable methods (each, collect,
etc) on a string, the string is split on \n first.  This meant the poor
stubbing didn't affect 1.8.7, but 1.9.2 is more strict and won't
automatically convert when you call enumerable methods on strings.

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