Added singular entity labels.

A new attribute label_singular has been added to all entities which
contains the singular form of the entity label in lower cases except
for acronyms (e.g. HBAC) or proper nouns (e.g. Kerberos). In the Web
UI, this label can be capitalized using CSS text-transform.

The existing 'label' attribute is intentionally left unchanged due to
inconsistencies in the current values. It contains mostly the plural
form of capitalized entity label, but some are singular. Also, it
seems currently there is no comparable capitalization method on the
server-side. So more work is needed before the label can be changed.

Ticket #1249

ipalib/plugins/group.py

@@ -98,6 +98,7 @@ class group(LDAPObject):
     rdnattr = 'cn'
 
     label = _('User Groups')
+    label_singular = _('user group')
 
     takes_params = (
         Str('cn',