Reimplemented BLIS initialization/finalization.

Details:
- Rewrote bli_init() and bli_finalize() with OpenMP critical sections
  for thread-safety. Also added lots of explanatory comments.
- Renamed bli_init_safe() and bli_finalize_safe() with the _auto()
  suffix, and reimplemented for simplicity. Updated all invocations
  in BLAS compatibility layer to use _auto() suffix.