Merge branch 'ELASTIX-14-Overlord' into develop

Modules/Components/Examples/src/Metric3rdPartyWrapper.cxx

Modules/Components/Examples/src/Metric4thPartyWrapper.cxx

Modules/Components/Examples/src/MetricComponent1.cxx

...es/Components/Examples/src/SSDMetric3rdPartyComponent.cxx

...es/Components/Examples/src/SSDMetric4thPartyComponent.cxx

Modules/Components/Examples/src/TransformComponent1.cxx

Modules/Core/ComponentInterface/include/ComponentBase.h

Modules/Core/ComponentInterface/include/ComponentSelector.h

Modules/Core/ComponentInterface/include/Overlord.h

Modules/Core/ComponentInterface/src/ComponentBase.cxx

Modules/Core/ComponentInterface/src/ComponentSelector.cxx

Modules/Core/ComponentInterface/src/Overlord.cxx

Modules/Core/ModuleCore.cmake

Testing/Unit/CMakeLists.txt

Testing/Unit/elxComponentFactoryTest.cxx

Testing/Unit/elxOverlordTest.cxx