[patch] Fix for JavaHL copy sources bug reported by Alexander Kitaev

oka reported this today on IRC. He mentioned that he'd have a chance
to test it out over the weekend. We could use some improved test coverage
here, not necessarily for the deprecated API in this patch, but for the
various permutations of CopySource usage in general.

oka, if this patch works out for you, please expand on the summary of my
change log message, as it doesn't properly capture the use cases involved
here. Assuming this works out, I'll propose it for backport to 1.5.1.

-- 
Daniel Rall
[[[
JavaHL: Fix bug in handling of peg revisions for copy sources.
[ subversion/bindings/javahl/ ]
* native/CopySources.cpp
  (CopySources::array): Set peg revision from the peg revision passed in from
    Java, rather than from the revision passed in.
* src/org/tigris/subversion/javahl/SVNClient.java
  (copy): Pass null in lieu of Revision.HEAD for the copy source to handle
    sources which are WC paths @ WC revs.
]]]