- proper component-wise clamping for MinMax clamp().
- construct clampOp from components
- propagate clamp() method from GeometricField to FieldField and Field
- clamp_min() and clamp_max() for one-sided clamping,
as explicit alternative to min/max free functions which can
be less intuitive and often involve additional field copies.
- top-level checks to skip applying invalid min/max ranges
and bypass the internal checks of MinMax::clamp() etc.
- 'unfriend' operators on dimensionSet, since they operate without
requiring access to non-public members.
- add missing invTransform() function for dimensionSet.
- make inv(const dimensionSet&) available as
operator~(const dimensionSet&), which can be used instead
of (dimless/ds).
