Adding rails3 support

Hello,

Thanks for creating lumber, I've not done much with rails, but am starting to do a little.  I'm sorta toying with the idea of pulling the features of lumber into log4r itself, but wasn't sure if that would be rude.

In anycase, I wanted to go ahead and use lumber in another project, which is based on rails3, so I've started adding in bits to make lumber work with rails3 generators.  While working with your Rakefile, I inadvertantly commited a VERSION change, which you probably don't want to pull into your source tree.

Cheers,
Colby