* Use helper funcs in hreflect package when possible.
* Use hreflect.ConvertIfPossible to handle conversions when possible.
* Move scratch.go from common/maps to common/hstore to clear cyclic import in the next step.
* Move Indirect to hreflect and reimplementing it and adusting the behavior to preserve struct pointers.
* Adjust evaluateSubElem used by where and others making the struct pointer method case slightly faster.
Bjørn Erik Pedersen