Make footer credit logos HiDPI-friendly

[melchoyce]

They're blurry on retina/HiDPI screens:

[melchoyce]

There are two options here:

1. Add in 2x png versions of the logos
2. Swap the pngs out for inline SVGs

2x pngs are easiest, and already the convention being used. However, this could be a good place to try introducing inline SVGs, which will be more future-proof.

What kind of browser support does jquery-wp-content maintain?

[arthurvr]

What kind of browser support does jquery-wp-content maintain?

IE8+

[jdorfman]

MaxCDN and Wordpress logos are in Font Awesome:

• http://fontawesome.io/icon/maxcdn/
• http://fontawesome.io/icon/wordpress/

Since jquery.com already uses Font Awesome, this would be as easy as replacing the logos with:

• <i class="fa fa-maxcdn"></i>
• <i class="fa fa-wordpress"></i>

As for Media Temple, a request can be made.

[melchoyce]

Looks like there's a Media Temple issue already: FortAwesome/Font-Awesome#1531

Font Awesome would work well for the other two. Maybe for now we can replace MaxCDN and WordPress with Font Awesome, and add a 2x png for Media Temple? Happy to make a PR.

[Krinkle]

Done in 28542b5.