qmlplugindump: correctly merge composite types
qmlplugindump: correctly merge composite types

When hiding part of the hierarchy during the merging of composite
types properties/methods/signals that are hidden should not be dumped
twice.

Task-number: QTBUG-38354
Change-Id: I328cf25dd5a70e1c0fce017e8ae572e8a9e56245
Reviewed-by: Shawn Rutledge <7b40856c8c1100512025516d7c58756d644d9e8d@digia.com>
Reviewed-by: Alan Alpert <da25f2afbbb946022229108d81aeba0c6b35c5c3@blackberry.com>

mgrunditz/qtdeclarative-2d,mgrunditz/qtdeclarative-2d,qmlc/qtdeclarative,qmlc/qtdeclarative,qmlc/qtdeclarative,mgrunditz/qtdeclarative-2d,mgrunditz/qtdeclarative-2d,mgrunditz/qtdeclarative-2d,qmlc/qtdeclarative,qmlc/qtdeclarative,mgrunditz/qtdeclarative-2d,qmlc/qtdeclarative,qmlc/qtdeclarative,qmlc/qtdeclarative,mgrunditz/qtdeclarative-2d