- tiles are in the VVC spec for 3 meeting cycles now
- cleanup helps with adaptation for tiles to current draft

VTM version 4.2

includes:
- rename flag HandleCraAsBlaFlag to HandleCraAsCvsStartFlag
- changes of NAL unit types (reduced number)
- profile_tier_level and general_constraint_info structures

- remove duplicate ALF parameters from Slice
- add activation (to avoide overwriting when a new APS arrives)
- rename macro

- all elements of SPSNext are moved into SPS
- syntax elements of SPS are sorted according to draft (as far as possible)
- comments were added where software and draft diverge