Patch from Pedro Ferreira to implement <tag> feature.

* new/targets.jam
  (basic-target.tag-name): New rule.
  (basic-target.generate-really): Temporary change self.name

* test/tag.py: New test.


[SVN r19298]

tools/build

@@ -1 +1 @@
-Subproject commit 9f5c3c21af1b0b0286ebe42b50528bfa94e52091
+Subproject commit 86c21bd2023821ef77d0c945d47dfa350ab9b211