Log Message:
Update ruby-diff-lcs to 1.2.4.

=== 1.2.4 / 2013-04-20

* Bugs fixed:
  * A bug was introduced after 1.1.3 when pruning common sequences at the start
    of comparison. Paul Kunysch (@pck) fixed this in pull request 18. Thanks!
    https://github.com/halostatue/diff-lcs/pull/18
* The Rubinius (1.9 mode) bug in rubinius/rubinius#2268 has been fixed by the
  Rubinius team two days after it was filed. Thanks for fixing this so quickly!
  https://github.com/rubinius/rubinius/issues/2268
* Switching to Raggi's hoe-gemspec2 for gemspec generation.

== 1.2.3 / 2013-04-11

* Bugs Fixed:
  * The new encoding detection for diff output generation (added in 1.2.2)
    introduced a bug if the left side of the comparison was the empty set.
    Originally found in rspec/rspec-expectations#238 and
    rspec/rspec-expectations#239. Jon Rowe developed a reasonable heuristic
    (left side, right side, empty string literal) to avoid this bug.
    https://github.com/rspec/rspec-expectations/pull/238
    https://github.com/rspec/rspec-expectations/pull/239
* There is a known issue with Rubinius in 1.9 mode reported in
  rubinius/rubinius#2268 and demonstrated in the Travis CI builds. For all
  other tested platforms, diff-lcs is considered stable. As soon as a suitably
  small test-case can be created for the Rubinius team to examine, this will be
  added to the Rubinius issue around this.
  https://github.com/rubinius/rubinius/issues/2268
  https://travis-ci.org/halostatue/diff-lcs/jobs/6241195

== 1.2.2 / 2013-03-30

* Bugs Fixed:
  * Diff::LCS::Hunk could not properly generate a difference for comparison
    sets that are not US-ASCII-compatible because of the use of literal regular
    expressions and strings. Jon Rowe (JonRowe) found this in
    rspec/rspec-expectations#219 and provided a first pass implementation in
    diff-lcs#15. I've reworked it because of test failures in Rubinius when
    running in Ruby 1.9 mode. This coerces the added values to the encoding of
    the old dataset (as determined by the first piece of the old dataset).
    https://github.com/rspec/rspec-expectations/issues/219
    https://github.com/halostatue/diff-lcs/pull/15
* Adding Travis CI testing for Ruby 2.0.