Handle <dependency> for 'stage'.

* tools/stage.jam
  (copy-file, relink-file): Add stage's dependency properies to
  the staged targets properties, so that <dependency> is copied too.

* test/stage.py: New test.


[SVN r26420]

tools/build

@@ -1 +1 @@
-Subproject commit 7d8f3051b8908ac698642a58a17c50fc0627fe25
+Subproject commit 6f86fbc1f4c11eec63a52edcd6d3494a5f954fa4