r12858: This moves the libnet_LookupPdc code to use a GetDC request to find

r12858: This moves the libnet_LookupPdc code to use a GetDC request to find
the remote server's name, or in the absence of a local nbt_server to
communicate with (or without root access), a node status request.

The result is that we are in a better position to use kerberos, as well
as to remove the 'password server' mandatory parameter for the samsync
and samdump commands.  (I need this to put these into SWAT).

The only problem I have is that I must create a messaging context, which
requires a server ID.  As a client process, I don't expect to get
messages, but it is currently required for replies, so I generate a
random() number.  We probably need the servers to accept connections on
streamed sockets too, for client-only tasks that want IRPC.

Because I wanted to test this code, I have put the NET-API-* tests into
our test scripts, to ensure they pass and keep passing.  They are good
frontends onto the libnet system, and I see no reason not to test them.

In doing so the NET-API-RPCCONNECT test was simplified to take a
binding string on the command line, removing duplicate code, and
testing the combinations in the scripts instead.

(I have done a bit of work on the list shares code in libnet_share.c
to make it pass 'make test')

In the future, I would like to extend the libcli/findds.c code (based
off volker's winbind/wb_async_helpers.c, which is why it shows up a bit
odd in the patch) to handle getting multiple name replies, sending a
getdc request to each in turn.

(posted to samba-technical for review, and I'll happily update with
any comments)

Andrew Bartlett
(This used to be commit 7ccddfd3515fc2c0d6f447c768ccbf7a220c3380)