bump __version__
fixed pyflakes warnings
pep8 style fixes
updated CHANGES.txt
wrote What's New for 0.4.2
updated __credits__
updated copyright notices
doc change proofreading
use bz2 compression in hadoop cookbook (now that mrjob can handle it!)
Merge pull request #828 from davidmarin/v0.4.2-release

Final cleanup for v0.4.2 release