* call-agent.c (start_agent): Create and pass the list of FD to
keep in the child to assuan.
* call-dirmngr.c (start_dirmngr): Ditto.
* scdaemon.c (main): Use GNUPG_DEFAULT_HOMEDIR constant.
* assuan-pipe-connect.c (assuan_pipe_connect): No special handling
for the log_fd and stderr. Connect stderr to /dev/null if it
should not be retained.
* assuan-pipe-connect.c: this.
(assuan_pipe_disconnect): Removed.
(do_finish, do_deinit): New
(assuan_pipe_connect): and set them into the context.
* assuan-socket-connect.c: New.
* assuan-util.c (_assuan_log_sanitized_string): New.
* assuan-pipe-server.c (assuan_init_pipe_server): Factored most
code out to ...
(_assuan_new_context): new func.
(_assuan_release_context): New
* assuan-connect.c (assuan_pipe_connect): Use the new functions.
