Fix assortment of bugs

karaage/datastores/ldap_datastore.py: Make sure we remove any group
assignments before deleting account, as they will remain otherwise.

karaage/machines/models.py: Make sure person is added to project
when creating new account.

karaage/machines/models.py: When deactivating account, don't remove
person from project.

karaage/people/models.py: Clear all groups when deactiving person.

karaage/projects/utils.py: Remove NOP save operation.

karaage/people/views/user.py: project_set renamed to projects.

Change-Id: I214d66d5d0c3ffdff8a5e50612553e2dbf3593b2
Fix logging signal handler.

Don't send log message multiple times for every user account.

Make sure log message is logged even when no accounts for person.

We need to respond to pre_clear not post_clear in order to list members
that will be cleared.

Change-Id: I8756f640db1ffff7de4c61993e1aa5fb5acf4121
Fix deleting default group.

When removing group from person ensure any accounts that
have this group as default_group are deactivated.

Change-Id: Iea816c0197264baa921ddc330fa71dedd35271bc