[cmake] fix dependency check target names, closes #177 (again)

cmake/DuneUtils.cmake

@@ -55,7 +55,7 @@ ENDMACRO( HEADERCHECK )
 MACRO( DEPENDENCYCHECK )
     ADD_CUSTOM_TARGET( dependenycheck SOURCES ${ARGN} )
     FOREACH( HEADER ${ARGN} )
-        GET_FILENAME_COMPONENT( fn ${HEADER} NAME )
+	string(REPLACE "/" "_" fn ${HEADER})	
         SET( TEST_NAME "dependenycheck_${fn}")
         TO_LIST_SPACES( MY_CXX_FLAGS TEST_NAME_FLAGS )
         SET(XARGS ${TEST_NAME_FLAGS} -DHAVE_CONFIG_H -H -c ${HEADER} -w)