added new selinux fact to clarify python lib

the selinux fact is boolean false when the library is not installed,
a dictionary/hash otherwise, but this is ambigous
added new fact so we can eventually remove the type dichtomy and normalize it as a dict

lib/ansible/module_utils/facts.py

@@ -443,8 +443,10 @@ class Facts(object):
     def get_selinux_facts(self):
         if not HAVE_SELINUX:
             self.facts['selinux'] = False
+            self.facts['selinux_python_present'] = False
             return
         self.facts['selinux'] = {}
+        self.facts['selinux_python_present'] = True
         if not selinux.is_selinux_enabled():
             self.facts['selinux']['status'] = 'disabled'
         else: