Use the import rule

[SVN r19968]

test/Jamfile

@@ -17,8 +17,7 @@
 subproject libs/conversion/test ;
 
 # bring in rules for testing
-SEARCH on testing.jam = $(BOOST_BUILD_PATH) ;
-include testing.jam ;
+import testing ;
 
 # Make tests run by default.
 DEPENDS all : test ;