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.
Octopress init
Site updated at 2013-11-21 19:46:17 UTC
Site updated at 2013-11-21 19:51:49 UTC
Site updated at 2013-11-21 19:53:16 UTC
Set the codepage to 65001 before generating
Add check for running on Windows
chcp only needs to run once
Fix spelling error
Merge pull request #1443 from wickedshimmy/patch-1

Fix spelling error
Add note about current stable version of Octopress to README.

Fixes #1451.
Merge pull request #1431 from Haacked/windows-code-page-fix

Set the codepage to 65001 before generating
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
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