Octopress no longer listens to .preview-mode, and History.markdown seems to be supplanted by CHANGELOG.markdown.
Update clean/clobber tasks to get JS assets and be more informative about what's going on.
Using File.join more consistently.
Bring over changes from History.markdown...
Merge pull request #1204 from MrJoy/update_clean_and_clobber

Update clean/clobber tasks to get JS assets and...
Merge pull request #1203 from MrJoy/cruft_removal

Octopress no longer listens to .preview-mode, and History.markdown seems...
Merge branch '2.1' of git://github.com/imathis/octopress into testing-2.1