NIS API changes

[Dan Williams <dcbw redhat com>]

Hi,

Specifically, the "nis-domainname" and "nis-servers" properties have
been removed from the NMIP4Config object as exported over D-Bus and from
libnm-glib.  I've removed any code dealing with NIS from NM itself; this
is better handled through dispatcher scripts.

The NIS information in reality only comes via DHCP, and thus doesn't
need to be composited with anything.  I've attached a compile-tested
dispatcher script that moves the code that was previously in
NetworkManagerSuSE.c into a standalone helper.  To enable this, I
earlier committed functionality in the dispatcher to dump available DHCP
options into the dispatcher script environment.

Dan