This reverts commit c5bea524.

This reverts commit b18f6cc1.

Now also moved to within layer iteration loop.

Replaced with point::max wherever possible. Is VGREAT, not GREAT so be
careful with calculations.

Have weight=7 on cells to be refined and balance. Then after refinement
there will be perfect balancing. Similar for layer addition.

Some tools now output sets at the pointsInstance (if relating to geometry),
some at the facesInstance (if relating to topology).
So when loading them we now search for them from current time down
to facesInstance. They cannot be beyond facesInstance.
Adapted Time::findInstance to take optional limiting instance. Adapted
topoSet to use this. Adapted all uses of IOobjectList on sets to do the
same.

and other unit conversion functions as they are required e.g. slug <-> kg.

- note left utilities/mesh/advanced/collapseEdges/collapseEdges.C as-is.
  It looks suspicious, but the change was recent, so maybe it means something