Add new build-time configuration feature.

test/all/Jamfile.v2

@@ -1,7 +1,7 @@
 #
 # Regression test Jamfile for boost configuration setup.
 # *** DO NOT EDIT THIS FILE BY HAND ***
-# This file was automatically generated on Wed May 28 17:13:04 2014
+# This file was automatically generated on Thu Jun 05 18:54:37 2014
 #  by libs/config/tools/generate.cpp
 # Copyright John Maddock.
 # Use, modification and distribution are subject to the