fixing for Diff::LCS::Change.from_a

flatten should only go one level deep to avoid problems when diffing arrays of arrays, e.g.:

Diff::LCS.sdiff([[1,2]], [])
RuntimeError: Invalid change array format provided.
        from /Users/joshbronson/homebase/jbro-homebase/bundle/ruby/1.9.1/gems/diff-lcs-1.2.4/lib/diff/lcs/change.rb:50:in `from_a'
        from /Users/joshbronson/homebase/jbro-homebase/bundle/ruby/1.9.1/gems/diff-lcs-1.2.4/lib/diff/lcs/change.rb:137:in `from_a'
        from /Users/joshbronson/homebase/jbro-homebase/bundle/ruby/1.9.1/gems/diff-lcs-1.2.4/lib/diff/lcs/change.rb:158:in `simplify'
        from /Users/joshbronson/homebase/jbro-homebase/bundle/ruby/1.9.1/gems/diff-lcs-1.2.4/lib/diff/lcs/callbacks.rb:312:in `discard_a'
        from /Users/joshbronson/homebase/jbro-homebase/bundle/ruby/1.9.1/gems/diff-lcs-1.2.4/lib/diff/lcs.rb:633:in `traverse_balanced'
        from /Users/joshbronson/homebase/jbro-homebase/bundle/ruby/1.9.1/gems/diff-lcs-1.2.4/lib/diff/lcs/internals.rb:10:in `diff_traversal'
        from /Users/joshbronson/homebase/jbro-homebase/bundle/ruby/1.9.1/gems/diff-lcs-1.2.4/lib/diff/lcs.rb:266:in `sdiff'
Merge pull request #23 from joshbronson/master

fixing for Diff::LCS::Change.from_a
Release 1.25: Bugfix for pull request #23.
Update htmldiff.rb

expand tabs is broken otherwise and the code is inconsistent anyway
Merge pull request #25 from hubrix/patch-1

Update htmldiff.rb
update Diff::LCS::Change and Diff::LCS::ContextChange's '==' methods to compare against the other object's class
Final changes for release 1.25.
Enabling code coverage.
Fixing a banner bug with bin/ldiff

Fixes #21.
Point to the GitHub repo as home.

- Until I can work up a better page.

Fixes #26.
Fixes #28.
Merge pull request #29 from GoBoundless/fix_compare

update Change and ContextChange's '==' methods to compare against the other object's class
Fix travis builds.
Bumping version in preparation for next release.
Fixing travis execution.
Merge pull request #1 from halostatue/master

latest from Austin Z.