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.

With msg level ERROR the message is printed to stderr

Bugfix for bugs 1 and 3 described in Y0190.
With adoption of Y0237 option C, legal bitstreams now and in the future cannot set gci_num_additional_bits to values in the range 1 to 5.
Decoder behaviour if it encounters such values is non-normative.

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