Refactor file to drop util_*

io_scene_niftools/__init__.py

io_scene_niftools/egm_import.py

io_scene_niftools/file_io/egm.py

io_scene_niftools/file_io/kf.py

io_scene_niftools/file_io/nif.py

io_scene_niftools/kf_import.py

io_scene_niftools/modules/nif_export/animation/__init__.py

io_scene_niftools/modules/nif_export/animation/material.py

io_scene_niftools/modules/nif_export/animation/morph.py

io_scene_niftools/modules/nif_export/animation/texture.py

io_scene_niftools/modules/nif_export/animation/transform.py

io_scene_niftools/modules/nif_export/armature/__init__.py

io_scene_niftools/modules/nif_export/block_registry.py

io_scene_niftools/modules/nif_export/collision/bound.py

io_scene_niftools/modules/nif_export/collision/havok.py

io_scene_niftools/modules/nif_export/constraint/__init__.py

...ene_niftools/modules/nif_export/geometry/mesh/__init__.py

io_scene_niftools/modules/nif_export/object/__init__.py

...niftools/modules/nif_export/property/material/__init__.py

...e_niftools/modules/nif_export/property/object/__init__.py