Log format changed: simpler timestamps
Log format changed: simpler timestamps

- localtime_r() or gmtime_r() can cause deadlocks
  inside glibc (if this logger is called via a signal
  handler) => use simpler format for the timestamp
- Errors and warnings are logged without timestamps,
  because the timestamp is now a big decimal number
  (might be confusing).

OlegGirko/ldbox,h113331pp/scratchbox2,ldbox/ldbox,ldbox/ldbox,ldbox/ldbox,OlegGirko/ldbox,OlegGirko/ldbox,h113331pp/scratchbox2,h113331pp/scratchbox2,ldbox/ldbox,h113331pp/scratchbox2,h113331pp/scratchbox2,ldbox/ldbox,OlegGirko/ldbox,ldbox/ldbox,h113331pp/scratchbox2,OlegGirko/ldbox,OlegGirko/ldbox