This fixes a bug in the Principal class when updating where
fields are set on the principal, but are not being updated and
end up getting set to NULL as a result.
In the new Scheduling Extensions for CalDAV the server is expected
to construct iCalendar METHOD:REQUEST invitations and put them into
the scheduling inbox for each (local) attendee. This patch does
that, and hopefully breaks the back of implementing the full
scheduling extensions.
This is a significant refactoring, replacing the old getUserBy*()
functions with a new Principal class, and replacing the old
CalDAVPrincipal class with a new DAVPrincipal class which extends
the Principal class.
At this point all regression tests pass (again) but there could
well be issues for people who use alternative authenticators
such as LDAP, although I have endeavoured to resolve those
potential issues.
Signed-off-by: Andrew McMillan <andrew@morphoss.com>
