theme swap relative to theme file

typo

Note that socket.io and a few others are not shipped by default

Ensure images are bound within the section

made page validate

Previously, descenders from characters like 'g' or 'y' were truncated (overflow: hidden)

woohoo! reveal.js is now HTML5 compliant! 

this is validated using the http://validator.w3.org/ and the http://html5.validator.nu/ services.

this was accomplished using a tad of JavaScript to get around a fullscreen bug.

This also (slightly unintentionally but helpfully) solves a tiny bug with fullscreening in old Opera 11.52 (I think, could be 11.51 or other)

added appropriate selection color

typo fix in index.html

Typo fix: let's -> lets

Cosmetic change in css/main.css

clarification of vertical/horizontal slide relation

rm extrenous whitespace

Clarified a bit how horizontal and vertical slides relate.

reveal.js was lacking a nice, simple, minimal theme. now it has one.
bam.

the old one was pink. while I don't have anything against pink, I just thought it might be good to make the highlight color dark brown instead.

themes are now available as separate css files under css/theme/, old theme option in config is no longer supported (closes #104)