*   Fixed missing line and shadow on service pages(404, 422, 500).

    *Dmitry Korotkov*

*   Removed repetitive th tags. Instead of them added one th tag with a colspan attribute.

    *Sıtkı Bağdat*

*   Added the Rails maintenance policy to the guides.

    *Matias Korhonen*

Please check [4-0-stable](https://github.com/rails/rails/blob/4-0-stable/guides/CHANGELOG.md) for previous changes.