turned off attribute warning on gnucc to alleviate spam with new boost and gcc 4.7

CMakeLists.txt

@@ -253,8 +253,9 @@ if (CMAKE_COMPILER_IS_GNUCXX)
   # with multiple -fno-strict-aliasing flags, triggering a complete rebuild whenever
   # cmake is run
   set (CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -fno-strict-aliasing")
+  set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-attributes")
   if(HIDDEN_VISIBILITY) 
-    set (CMAKE_CXX_FLAGS "-fvisibility=hidden")
+    set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fvisibility=hidden")
     set (_HIDDEN_VIS ON)
   else(HIDDEN_VISIBILITY)
     set (_HIDDEN_VIS OFF)