Simplify validation context
Remove validate function from interface
Rename adapt to preValidate to prepare for postValidate
Remove validating function interface
Remove inner class from FunctionAdapterImpl
Add postValidate method to adapter
Fix name
Test postValidation
Make FunctionAdapter methods static
FunctionAdapter relax should replace RepoFunctionInvoker
Use HippoProperty instead of Property
Add HippoValue so I can remove RepoFunction and invoker
Add HippoValue and a HippoEntityFactory