Progress reports on stderr if doing recovery from ha_maria;
don't do checkpoints if activity since last checkpoint < 2MB
(no change in fact as background thread is disabled for now);
recovery trace is only if EXTRA_DEBUG now (better for benchmarks).


storage/maria/ma_checkpoint.c:
  don't do checkpoints if activity (log writes plus page flushes)
  since last checkpoint was < 2MB.
storage/maria/ma_recovery.c:
  progress reports in recovery (10%, transactions left to rollback etc);
  that is only if from ha_maria and is displayed on stderr.
  Recovery trace is now created only if EXTRA_DEBUG.
storage/maria/ma_test_recovery.expected:
  update (--debug gone)
storage/maria/ma_test_recovery:
  don't use --debug, as it can absent from binary