Add animation libraries

[juliotaylor]

We should consider adding a couple of animation libraries to Bower, and include in the compiler, initially as an option (comment out by default).

The reason is we should start focusing on animation, and perhaps implement some basic subtle animation effects on the standard build in later releases. Initially, just include the libraries, and in a future release add basic animation to buttons and other bits.

Candidates for inclusion:

• http://ianlunn.github.io/Hover/
• https://daneden.github.io/animate.css/

[juliotaylor]

@jrgmartin @dmseaton @simonpmiles thoughts?