IE8 Fixes (part 2)

Three small fixes here:

* #434 - CSS tweaks: Adding fallback colors for `rgba`, and swapping `::after` for `:after`
* #435 - Enable CORS support in jQuery
* #430 - Click event handler changes
Ah. CSS3 added support for `::` because they're pseudo-_elements_ rather than pseudo-classes. But originally, the syntax was the same it seems.

> The ::after notation was introduced in CSS 3 in order to establish a discrimination between pseudo-classes and pseudo-elements. Browsers also accept the notation :after introduced in CSS 2.
Source: https://developer.mozilla.org/en-US/docs/Web/CSS/::after