r8076: Put name resolution methods into libnet_context. This allows libnet based

r8076: Put name resolution methods into libnet_context. This allows libnet based
application use methods of their own choice and makes it less dependent on
smb.conf parameters.
Use libnet_context in libnet_Lookup functions which is the way to pass
default name resolution methods if caller doesn't want to bother with
specifying them.

rafal
(This used to be commit d0ea136356bcb9c6c01120d8683b71e8689d5e5b)