r4570: Replace cli->nt_pipe_fnum with an array of NT file numbers, one for each

r4570: Replace cli->nt_pipe_fnum with an array of NT file numbers, one for each
supported pipe. Netlogon is still special, as we open that twice, one to do
the auth2, the other one with schannel.

The client interface is completely unchanged for those who only use a single
pie. cli->pipe_idx is used as the index for everything except the "real"
client rpc calls, which have been explicitly converted in my last commit. Next
step is to get winbind to just use a single smb connection for multiple pipes.

Volker