Corresponding recast mesh tiles can be updated but navmesh tiles may never
appear for them. Report back zero navmesh version to allow oscillating recast
objects detection to work. This version is always less than any generated
navmesh tile version so any report for generated navmesh will override it.
If zero navmesh version is reported after recast mesh tile got report about
generated navmesh tile it is a no-op since generated version is always greater
than zero.
To avoid triggering NavMesh update when RecastMesh change should not change
NavMesh.
Based on the following assumption:
Given a set of transformations and a bounding shape for all these
tranformations, a new object transformation that does not change this
bounding shape also should not change navmesh if for all of this object
transformations resulting navmesh tiles are equivalent
The idea is to report back to RecastMeshManager all changes of NavMesh if there
are any assiciated with RecastMesh version. So we know the last time when
RecastMesh change resulted into the NavMesh change. When later report shows
that there was no NavMesh change for a new RecastMesh version we can assume
that any object transformation within the same bounding box should not change
NavMesh.