(#21533) Verify facter doesn't write to stderr

This commit doesn't fix #21533, but it adds an acceptance test to detect
if executing `facter` writes to stdout.
(maint) Fix mocha expectations crashing facter_spec

Running `bundle exec rspec spec/unit/util/virtual_spec.rb
spec/unit/facter_spec.rb` prior to this patch would crash rspec outright
while the test harness was still loading.  This was because
virtual_spec.rb had expectations set in a shared_examples block but
outside of a before or it block.  These then caused an expectation
failure when explicit calls to Facter[:foo] were used as the description
in two describe calls in facter_spec.

This patch clears up both those misuses of rspec, and also adds the
log_spec_order method from Puppet for future bisecting of spec order
issues in Facter...which hopefully we won't have to do. :)
(maint) Rakefile loads all the libraries it can.

The call to load ext/packaging/packaging.rake will fail unless the
packaging system has been bootstrapped.  Previously this failure would
prevent attempts to load other libraries (notably rspec), and a `be rake
spec` would return silently without executing any specs.

Requires each lib separately so that failure to load one does not
prevent others.
(maint) Update README with a little bit of spec info.
Merge pull request #475 from jpartlow/maint/stable/virtual_and_facter_spec_order_fix

Maint/stable/virtual and facter spec order fix
Merge pull request #470 from joshcooper/ticket/stable/21533-facter-stderr

(#21533) Verify facter doesn't write to stderr
(maint) Clean up install.rb dependencies

The openssl, xmlrpc/client, and xmlrpc/server libraries are not used anywhere
in facter, so checking for them in facter serves no purpose. This commit
removes them from the list of PREREQS for facter.
(maint) Remove openssl dependencies from debian/control file

As openssl is not required or used by facter, this commit removes the
dependency from the facter debian package.
(packaging) Update changelog template with currently supported debian/ubuntu dists.
Merge pull request #477 from haus/maint/stable/packaging_fixes

Maint/stable/packaging fixes
Merge branch 'stable'