clean up the styles on the animation page a bit

I'm trying to keep as many styles as global as possible so that other
project pages and blog posts etc all have the same look and feel.
ajax load in the animations!

each animation requires two parts: the #animations div and the
corresponding stylesheet. since I have the urls listed and the css files
have the same name I can just load in these parts with javascript.

in order to insert the javascript and styles accordingly I had to insert
a couple of `yield_content` sections in the layout. I need to take
advantage of these on other pages now.
merge in update to css3_animations for captions

side bonus: also load them into the animations page. this ends up being
kind of weird with a div.caption containing a div#caption but ... eh
make ajax animation laoding more responsive

there wasn't any way to tell which animation was displayed other than
remembering which one you last clicked on. this gives it a bit more of a
visual 'oomf'