Don't reallocate/copy the multiblock address into the boundary structure,
take a copy instead.

Move the reuse flag into the WT_ADDR structure (there's room there).

Fix some memory leaks where the allocated address wasn't correctly
free'd in the multiblock case.
Memory leak: free the instantiated key in the split page reference.
Add a comment -- copy the multiblock address instead of just taking it,
and there's a reason.
Add support for a new verify option "-d dump_offsets=#,#,#", that allows
you to dump specific offsets in the target.
Merge pull request #939 from wiredtiger/new-split-memory

Fix some memory leaks, add support for dumping offsets in objects.