hbacrule: Create FQDN from single hostnames

Single hostnames can be used for hbacrule_add_host and will match fqdn
in IPA internally. Simple host names have to be extended to be FQDN to
be able to compare them for _host_add and _host_remove.

Two new functions have been added to ansible_freeipa_module:

- api_get_domain - Get the domain from the api
- ensure_fqdn - Extend a single name with the domain

This fixes #617 - hbacrule_add_host: already a member

plugins/module_utils/ansible_freeipa_module.py

@@ -370,6 +370,14 @@ else:
     def module_params_get(module, name):
         return _afm_convert(module.params.get(name))
 
+    def api_get_domain():
+        return api.env.domain
+
+    def ensure_fqdn(name, domain):
+        if "." not in name:
+            return "%s.%s" % (name, domain)
+        return name
+
     def api_get_realm():
         return api.env.realm