Add HeroDevs support.

[AndreAngelantoni]

This supports #462.

Within this, please find:

1. add status message top of screen on homepage
2. add Support menu item to navigation bar
3. change text on Download button; add a link below the button
4. add warning box to API pages (via a new category.php file)
5. add styling for the above.

Please examine and confirm the logic for the deprecated APIs...I read the instructions to mean "show the warning box" on the deprecated pages IF the version is EOL. Happy to change this if I got that wrong.

If a version is deprecated (the version is lower than 3.0), it will look like this:

The status bar looks like below and appears only on the home page of jquery.com:

The button text and link below look like this:

[timmywil]

I've take this PR and made some modifications. Closing in favor of #468