- revert nullptr check for BMap::MeshTrans pointer getter.
- fix pointer return error of BMap::MeshTrans
- fix type hint error and variable name error in PyBMap
- fix CKMesh flag init value error
- improve empty material slots saving. add a nullptr entry if no slots to make sure virtools can load it.
- provide lit mode and wrap mode getter and setter in CKMesh.
- add lost flags setter in CKMesh.
- show lit mode and wrap mode data in Unvirt.
- add interface for lit mode in BMap, because some old Ballance map use lit mode to light objects.
- expose a raw c callback when creating bmap to allow user decide how the log output by themselves.
- change python bindings for BMap interface changes.
