Require uniqueness in the name/comment field of delegations

Fix error reporting in the UI to include the detailed message
Sort delegations by name when displaying them
Update the name field from "Name" to "Delegation Name"

ipa-python/aci.py

@@ -37,6 +37,16 @@ class ACI:
         if acistr is not None:
             self.parse_acistr(acistr)
 
+    def __getitem__(self,key):
+        """Fake getting attributes by key for sorting"""
+        if key == 0:
+            return self.name
+        if key == 1:
+            return self.source_group
+        if key == 2:
+            return self.dest_group
+        raise TypeError("Unknown key value %s" % key)
+
     def export_to_string(self):
         """Converts the ACI to a string suitable for an LDAP aci attribute."""
         attrs_str = ' || '.join(self.attrs)