Implement versioning for native rules. This allows to change interface of

a native rule and have Boost.Build detect that and produce nice error, as
opposed to obscure one.


[SVN r31140]

tools/build

@@ -1 +1 @@
-Subproject commit 353359d5b007be171a75f41cc393d04bf7ae65c4
+Subproject commit 0581a1527001c18baf56f67eef4e723bfa750a59