Limit permission and selfservice names to alphanumerics, -, _, space

The DN and ACI code doesn't always escape special characters properly.
Rather than trying to fix it, this patch takes the easy way out and
enforces that the names are safe.

https://fedorahosted.org/freeipa/ticket/2585

tests/test_xmlrpc/test_selfservice_plugin.py

@@ -26,6 +26,7 @@ from tests.test_xmlrpc import objectclasses
 from xmlrpc_test import Declarative, fuzzy_digits, fuzzy_uuid
 
 selfservice1 = u'testself'
+invalid_selfservice1 = u'bad+name'
 
 class test_selfservice(Declarative):
 
@@ -270,4 +271,16 @@ class test_selfservice(Declarative):
             )
         ),
 
+        dict(
+            desc='Create invalid %r' % invalid_selfservice1,
+            command=(
+                'selfservice_add', [invalid_selfservice1], dict(
+                    attrs=[u'street', u'c', u'l', u'st', u'postalcode'],
+                    permissions=u'write',
+                )
+            ),
+            expected=errors.ValidationError(name='name',
+                error='May only contain letters, numbers, -, _, and space'),
+        ),
+
     ]