CMake build: export less generic public includes

Do not put every plugin's and lib's source folder into public includes.
We require includes of the style <somelib/foo.h> and <someplugin/bar.h>
if someone depends on somelib or someplugin.

Change-Id: I3a9f200b7c3879cf431b00a1bab4a70f7aa0a9ec
Reviewed-by: Cristian Adam <cristian.adam@qt.io>

src/tools/clangrefactoringbackend/source/CMakeLists.txt

@@ -10,6 +10,7 @@ add_qtc_library(clangrefactoringbackend_lib STATIC
   PUBLIC_INCLUDES
     ${CLANG_INCLUDE_DIRS}
     "../../clangpchmanagerbackend/source"
+    "${CMAKE_CURRENT_LIST_DIR}"
   SOURCES
     clangquery.cpp clangquery.h
     clangquerygatherer.cpp clangquerygatherer.h