Remove quotes+apostrophes from URLs for CloudFront

My `s3cmd sync` command has been failing with an error message of "Your request contains one or more invalid invalidation paths", which is annoying because then the files take forever to update. I figured out how to manually invalidate the files using the AWS Console, and used s3cmd to list the files and get the paths to invalidate, and then did a quick binary search to isolate the problematic files.

It seemed like CloudFront didn't like the invalidation requests for either of these:
	/2010/01/27/einstein's-theory-of-general-relativity-a-personal-description/index.html
	/2010/01/27/einstein’s-theory-of-general-relativity-a-personal-description/index.html

The documentation says I can URL-encode the apostrophe and quote characters, but I wasn't sure how to do that in my Rakefile from s3cmd, so it seemed easier just to change the posts permalink and add an S3 routing rule. It all works fine now, and I'll be more careful with my permalinks from now on :)

Also, ARGH, be careful about accidentally removing file extensions when moving files, sicne Jekyll will just ignore them...
Update GitHub URL in footer (removed "-octopress")