* NEWS: Document this.
* src/compare.c (verify_volume): Decode the header before invoking
diff_archive, as diff_archive no longer does this as of the
2010-06-28 commit. Also, don't try to invoke diff_archive on a
zero block.
* tests/Makefile.am (TESTSUITE_AT): Add verify.at.
* tests/testsuite.at: Include verify.at.
* tests/verify.at: New file.
