Refactor to use osfamily instead of operatingsystem

The notion of operatingsystem should be abstracted for most usages by
using osfamily (which gives windows, RedHat and Debian that I know of -
not sure about MacOS).

Some specific log files were missing from the default configuration for
mail filters.

spec/classes/fail2ban_spec.rb

@@ -26,7 +26,7 @@ describe 'fail2ban' do
   end
 
   describe 'Test jails managed throuh file - template' do
-    let(:facts) { {:operatingsystem => 'Debian' } }
+    let(:facts) { {:osfamily => 'Debian' } }
     let(:params) { {:jails_config => 'file', :jails_template => 'fail2ban/jail.local.erb', :jails => 'ssh' } }
     it { should contain_file('jail.local').without_source }
     it { should contain_file('jail.local').with_content(/ssh-iptables\]