various little fixes (#1604)

* added AsTypeName to the context-sensitive commandbar

* clear built-in references at every resolution; fixed issue with null parse trees, given built-in modules get a module state instance.

* fixed OverflowException in GetTypeName; built-in parameters now have return type info :)

* returning built-in members now have return type info as well

* removed hard-coded defaults in ClassModuleDeclaration

* added IsBadReadPtr check in COM declarations collector

* Implemented CanExecute in Project Explorer rename command

* cleaned up FormDesignerRefactorRename command

* fixed IOExceptions in QualifiedModuleName

* use filename, not buildfilename

* GetDisplayName being the part in parens, should be null when not applicable; made it private

Author: retailcoder