Improve handling of features. Now they are composed only of explicitly

specified properties.

* new/builtin.jam: (variant): Don't add defaults.

* new/feature.jam: (minimize): Eliminate defauls, when possible.


[SVN r17066]

tools/build

@@ -1 +1 @@
-Subproject commit ee7abc0343e431e0df86ec86fe45f559081770d3
+Subproject commit b67df40f139cfba4673c72519e3604243c068024