private includes for QtDesigner plugin

SHSTKQtMacros.cmake

@@ -101,6 +101,11 @@ macro(shstk_qad_plugin NAME _MODULES _LIBS)
 			qad_wrap(${SRC} CPPS out_CPP QMS out_QM)
 			qad_add_library(${PROJ_NAME} SHARED out_CPP)
 			qad_target_link_libraries(${PROJ_NAME} ${_LIBS} ${_${NAME}_PLUGIN_LIBS})
+			foreach(_v ${_QT_VERSIONS_})
+				if (LOCAL_FOUND${_v})
+					target_include_directories(${PROJ_NAME}${TARGET_SUFFIX_Qt${_v}} PRIVATE "${Qt${_v}Designer_PRIVATE_INCLUDE_DIRS}")
+				endif()
+			endforeach()
 			if (WIN32)
 				qad_install(TARGETS ${PROJ_NAME} RUNTIME DESTINATION QtPlugins/designer)
 			else()