The default -1 was compared to an unsigned int, which implied casting -1 to unsigned and thus created a number larger than the allowed maximum.

for this condition in encoder.

Improve fix: now merge splitting works correctly for independent layers, even those not including layer 0.

Fix a decoder crash in multi-layer context when using e.g. ALF and -p 0: reset APS NALs for a skipped layer.

This reverts commit 9eca063e.

- restore TemporalFilter parameter
- print warning when parameters are outside set that has been
  extensively tested