CMake : Ensure we define local include paths before external paths

contrib/cmake/CMakeLists.txt

@@ -92,6 +92,7 @@ find_package( Qt5 5.6 REQUIRED Core Gui OpenGL )
 find_package( Appleseed REQUIRED )
 find_package( OpenVDB REQUIRED )
 
+include_directories( ${GAFFER_SOURCE_DIR}/include )
 include_directories( ${TBB_INCLUDE_DIRS} )
 include_directories( ${PYTHON_INCLUDE_DIRS} )
 include_directories( ${Boost_INCLUDE_DIRS} )
@@ -101,7 +102,6 @@ include_directories( ${Cortex_INCLUDE_DIRS} )
 include_directories( ${FREETYPE_INCLUDE_DIRS} )
 include_directories( ${CORTEX_ARNOLD_INCLUDE_PATH} )
 include_directories( ${APPLESEED_INCLUDE_DIRS} )
-include_directories( ${GAFFER_SOURCE_DIR}/include )
 
 link_directories( ${TBB_LIBRARY_DIRS} )
 link_directories( ${Boost_LIBRARY_DIRS} )