server: Simplify process creation.

Pass the socket for the new process from the parent through the
environment.
Perform initialisations during the new_process request.
diff --git a/server/request.c b/server/request.c
index a78916e..260fc62 100644
--- a/server/request.c
+++ b/server/request.c
@@ -508,7 +508,7 @@
             sock->timeout = NULL;
         }
         fcntl( client, F_SETFL, O_NONBLOCK );
-        create_process( client );
+        create_process( client, NULL, 0 );
     }
 }