Fixed blog_url not returning & rake setup_github_pages failing

When executing `rake setup_github_pages`, an error tells that `url` don't exist. The reference to that variable has been changed to a call to `blog_url`.

The function `blog_url` was not returning anything, failing to properly write the `_config.yml` file. It now does return what should have.
Fixed blog_url when user contains uppercase letters
Made blog_url becalled just once...

...and stored in the `url` variable.
Reversed update_style copy direction to correctly restore the sass.old/custom files to the new sass/custom folder
Fix typo in update_style copy command
Octopress init
Site updated at 2014-02-24 01:13:00 UTC
Site updated at 2014-02-24 01:34:55 UTC
Site updated at 2014-02-24 01:56:20 UTC
Site updated at 2014-02-24 01:59:54 UTC
Site updated at 2014-02-24 02:06:54 UTC
Site updated at 2014-02-24 02:12:05 UTC
Site updated at 2014-02-24 02:21:59 UTC
Site updated at 2014-02-24 03:44:42 UTC
Site updated at 2014-02-24 04:40:09 UTC
Site updated at 2014-02-24 04:45:54 UTC
Ignore protocol relative '//' urls.
Removed accidental call to expand_url
Fixed the expand_url filter. Finally.

Thanks @larryprice
gist_plugin: Handle multiple redirects, stopping if we find a circular reference