Refactoring: IModuleResolver fully Lang only code.
Refactor out some uses of resolveDefUnit
Refactored resolveUnderlyingNode to ILangElement
Remove unnecessary source setting.
Refactored out redudant DirectDefUnitResolve into FindDefResult
Reorganization of the Lang structure of INamedElement
Many intermediate refactoring/changes: 
Added nodeSemantics, initial template instantiation.
DefinitionAggregate use NodeSemantics.
Refactor: make all nodes use new NodeSemantics API