(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