Use SOURCE_DIR instead of CMAKE_DIR for build tree

CMakeLists.txt

@@ -181,7 +181,7 @@ EXPORT( PACKAGE ${PROJECT_NAME} )
 # ... for the build tree
 SET( CONFIG_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
 SET( CONFIG_DIR ${CMAKE_CURRENT_BINARY_DIR})
-SET( ${PROJECT_NAME}_INCLUDE_DIR "\${${PROJECT_NAME}_CMAKE_DIR}/include" )
+SET( ${PROJECT_NAME}_INCLUDE_DIR "\${${PROJECT_NAME}_SOURCE_DIR}/include" )
 
 CONFIGURE_FILE( ${CMAKE_CURRENT_SOURCE_DIR}/${PROJECT_NAME}Config.cmake.in
     ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}Config.cmake @ONLY )