r12411: Add 'net samdump keytab <keytab>'.

r12411: Add 'net samdump keytab <keytab>'.

This extracts a remote windows domain into a keytab, suitable for use
in ethereal for kerberos decryption.

For the moment, like net samdump and net samsync, the 'password
server' smb.conf option must be set to the binding string for the
server. eg:

password server = ncacn_np:mypdc

Andrew Bartlett
(This used to be commit 272013438f53bb168f74e09eb70fc96112b84772)