(connect_wait_mask, num_pending_connects): Only

(connect_wait_mask, num_pending_connects): Only
declare and use them if NON_BLOCKING_CONNECT is defined.
(IF_NON_BLOCKING_CONNECT): New helper macro.
(wait_reading_process_output): Only declare and use local vars
Connecting and check_connect when NON_BLOCKING_CONNECT is defined.
(init_process): Initialize them if NON_BLOCKING_CONNECT defined.