ENH: Use new COMPILE_DEFINITIONS_* with set_property to

      add Qt release/debug defines.

Modules/UseQt4.cmake

@@ -5,17 +5,10 @@
 
 
 ADD_DEFINITIONS(${QT_DEFINITIONS})
-
-# check that QT_NO_DEBUG is defined for release configurations
-MACRO(QT_CHECK_FLAG_EXISTS FLAG VAR DOC)
-  IF(NOT ${VAR} MATCHES "${FLAG}")
-    SET(${VAR} "${${VAR}} ${FLAG}" 
-      CACHE STRING "Flags used by the compiler during ${DOC} builds." FORCE)
-  ENDIF(NOT ${VAR} MATCHES "${FLAG}")
-ENDMACRO(QT_CHECK_FLAG_EXISTS FLAG VAR)
-QT_CHECK_FLAG_EXISTS(-DQT_NO_DEBUG CMAKE_CXX_FLAGS_RELWITHDEBINFO "Release with Debug Info")
-QT_CHECK_FLAG_EXISTS(-DQT_NO_DEBUG CMAKE_CXX_FLAGS_RELEASE "release")
-QT_CHECK_FLAG_EXISTS(-DQT_NO_DEBUG CMAKE_CXX_FLAGS_MINSIZEREL "release minsize")
+SET_PROPERTY(DIRECTORY APPEND PROPERTY COMPILE_DEFINITIONS_DEBUG QT_DEBUG)
+SET_PROPERTY(DIRECTORY APPEND PROPERTY COMPILE_DEFINITIONS_RELEASE QT_NO_DEBUG)
+SET_PROPERTY(DIRECTORY APPEND PROPERTY COMPILE_DEFINITIONS_RELWITHDEBINFO QT_NO_DEBUG)
+SET_PROPERTY(DIRECTORY APPEND PROPERTY COMPILE_DEFINITIONS_MINSIZEREL QT_NO_DEBUG)
 
 INCLUDE_DIRECTORIES(${QT_INCLUDE_DIR})