[PATCH] assuan_socket_connect_fd().

[Ben Kibbey]

Attaches an existing connected file descriptor to an allocated
assuan_context_t. I have an app that uses libssh2 to connect to a remote
server over an SSH channel that executes a proxy to the server unix domain
socket. The server and client use the assuan protocol. Since the connection
needs to be done via SSH client hooks are needed for socket read and write
operations and the assuan context doesnt need to be connected by using the
other assuan functions. It only needs the protocol handshake done. Attached is
a patch to do this.

Thanks!