Qt Creator CMake port

Based on Tobias Hunger's work from a few months ago.

The CMake configuration needs libclang and Qt paths specified as
CMAKE_PREFIX_PATH.

Auto tests are run with "ctest". At the moment the pass rate is 87%.

Change-Id: Iba98e39bf22077d52706dce6c85986be67a6eab0
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/help/CMakeLists.txt

@@ -0,0 +1,45 @@
+add_qtc_plugin(Help
+  CONDITION TARGET Qt5::Help
+  DEPENDS shared_help
+  PLUGIN_DEPENDS Core ProjectExplorer
+  PLUGIN_RECOMMENDS TextEditor
+  SOURCES
+    centralwidget.cpp centralwidget.h
+    docsettingspage.cpp docsettingspage.h docsettingspage.ui
+    filtersettingspage.cpp filtersettingspage.h filtersettingspage.ui
+    generalsettingspage.cpp generalsettingspage.h generalsettingspage.ui
+    help.qrc
+    helpconstants.h
+    helpfindsupport.cpp helpfindsupport.h
+    helpindexfilter.cpp helpindexfilter.h
+    helpmanager.cpp helpmanager.h
+    helpmode.cpp helpmode.h
+    helpplugin.cpp helpplugin.h
+    helpviewer.cpp helpviewer.h
+    helpwidget.cpp helpwidget.h
+    localhelpmanager.cpp localhelpmanager.h
+    openpagesmanager.cpp openpagesmanager.h
+    openpagesmodel.cpp openpagesmodel.h
+    openpagesswitcher.cpp openpagesswitcher.h
+    openpageswidget.cpp openpageswidget.h
+    remotehelpfilter.cpp remotehelpfilter.h remotehelpfilter.ui
+    searchtaskhandler.cpp searchtaskhandler.h
+    searchwidget.cpp searchwidget.h
+    textbrowserhelpviewer.cpp textbrowserhelpviewer.h
+    xbelsupport.cpp xbelsupport.h
+)
+
+if (APPLE)
+  find_library(FWWebKit WebKit)
+  find_library(FWAppKit AppKit)
+  target_link_libraries(Help PRIVATE ${FWWebKit} ${FWAppKit})
+  target_compile_definitions(Help PRIVATE QTC_MAC_NATIVE_HELPVIEWER)
+  target_sources(Help PRIVATE macwebkithelpviewer.h macwebkithelpviewer.mm)
+endif()
+
+find_package(Qt5WebEngineWidgets QUIET)
+
+if (TARGET Qt5::WebEngineWidgets)
+  target_sources(Help PRIVATE webenginehelpviewer.cpp webenginehelpviewer.h)
+  target_link_libraries(Help PRIVATE Qt5::WebEngineWidgets)
+endif()