Code for comparisons.

- Diff.java - the main Diff program,

        /**
         * BSD-licensed Java implementation of "An O(ND) Difference Algorithm
         * and its Variations" by Eugene Myers, published in
         * Algorithmica Vol. 1 No. 2, 1986, p 251.
         *
         * C# version written by Mathias Hertel, http://www.mathertel.de
         * Mathias Hertel's version ported to Java by Ian Darwin, http://www.darwinsys.com/
         */

- DiffObj.java - compare Java objects by field, report which fields are different
- DiffChunk.java, DiffType.java - part of a facility for reporting diffs, not used yet