Provide more useful progress reporting of crash recovery.

recv_sys_t::progress_time: The time of the last report.

recv_sys_t::report(ib_time_t): Determine whether progress should
be reported.

recv_scan_print_counter: Remove.

log_group_read_log_seg(): After after each I/O request, invoke
recv_sys_t::report() and report progress if needed.

recv_apply_hashed_log_recs(): Change the return type back to void
(DB_SUCCESS was always returned), and rename the parameter to last_batch.
At the start of each batch, if there are pages to be recovered,
issue a message.