This reverts commit 5d0e99a3.

This reverts commit 983453e2.

This was added by the Doom developers to work around the issue where
objects were not linked into all blockmap cells they were touching, and
instead just the one at the object's center. Since this is no longer
the case after commit 41613d89,
this adjustment is no longer necessary.

adjust interpolation duration based on speed, allow anim_duration to be used as a lua override to hardcoded values

This reverts commit e67e225f.

This reverts merge request !2334