nmbd: add support for delayed initial samlogon packages.

nmbd: add support for delayed initial samlogon packages.

The hosts or networks configured with "init logon delayed hosts"
have their initial samlogon packages (empty username) delayed
by the value configured with "init logon delay" (defaulting
to 100 milliseconds).

This gives the administrator some control over what clients would
consider the preferred logon server: they choose the server that
repsonds most quickly.

Michael
(This used to be commit d52b9beede1fb14e1d7e3acd9765d6cd14dfcc3d)