[CMake] Add SYSTEM info to INCLUDE_DIRECTORIES macro

It removes useless warnings

CMakeLists.txt

@@ -144,7 +144,7 @@ SET(BOOST_OPTIONAL_COMPONENTS "")
 IF(BUILD_PYTHON_INTERFACE)
   SET(BOOST_OPTIONAL_COMPONENTS ${BOOST_OPTIONAL_COMPONENTS} python)
   FINDPYTHON(2.7 EXACT REQUIRED)
-  INCLUDE_DIRECTORIES(${PYTHON_INCLUDE_DIRS}) 
+  INCLUDE_DIRECTORIES(SYSTEM ${PYTHON_INCLUDE_DIRS}) 
 ENDIF(BUILD_PYTHON_INTERFACE)
 
 SET(BOOST_COMPONENTS ${BOOST_REQUIERED_COMPONENTS} ${BOOST_OPTIONAL_COMPONENTS} ${BOOST_BUILD_COMPONENTS})
@@ -154,7 +154,7 @@ SEARCH_FOR_BOOST()
 SET(CFLAGS_DEPENDENCIES)
 
 # Path to boost headers
-INCLUDE_DIRECTORIES(${Boost_INCLUDE_DIRS})
+INCLUDE_DIRECTORIES(SYSTEM ${Boost_INCLUDE_DIRS})
 
 # ----------------------------------------------------
 # --- INCLUDE ----------------------------------------