r10314: Apply the controvertial 'server role =' patch after discussion on the list:

r10314: Apply the controvertial 'server role =' patch after discussion on the list:

This patch removes the 'domain logon' and 'domain master' controls from
Samba4, in favour of a 'server role =' that users can actually
understand.

We can expand the list of roles as needed, and nobody has to figure out
what a 'domain master' actually means.

Andrew Bartlett
(This used to be commit 31e755c2ced64dbd2681d5f6ef021a87dbeda689)