implement user database deletion

- modify userdbs.models.UserDatabase.delete to perform deletion of database
  user if it has no other databases assigned
- implement userdbs.views.DeleteUserDatabase
- add URL pattern 'delete_userdatabase' to userdbs.urls
- add template userdbs/userdatabase_confirm_delete.html
- add link to 'delete_userdatabase' on hosting package detail page
- add changelog entry

gnuviechadmin/userdbs/urls.py

@@ -9,6 +9,7 @@ from django.conf.urls import patterns, url
 from .views import (
     AddUserDatabase,
     ChangeDatabaseUserPassword,
+    DeleteUserDatabase,
 )
 
 urlpatterns = patterns(
@@ -17,4 +18,6 @@ urlpatterns = patterns(
         AddUserDatabase.as_view(), name='add_userdatabase'),
     url(r'^(?P<package>\d+)/(?P<slug>[\w0-9]+)/setpassword',
         ChangeDatabaseUserPassword.as_view(), name='change_dbuser_password'),
+    url(r'^(?P<package>\d+)/(?P<slug>[\w0-9]+)/delete',
+        DeleteUserDatabase.as_view(), name='delete_userdatabase'),
 )