[reveal.js] Updated the embedded reveal.js

We're now at 793409 and that's roughly where reveal.js was on September
6th, 2013.
[version] Version Bump: 0.1.4

Release is upcoming. Following http://semver.org. Still haven't hit
"1.0", so just doing a patch bump. However, have added new
functionality-- so would be a minor if I was past 1.0.
[Gemfile.lock] Gems shouldn't have a Gemfile.lock

This article is my motivation:

http://yehudakatz.com/2010/12/16/clarifying-the-roles-of-the-gemspec-and-gemfile/
[doc] README is now slim+haml aware
[doc] Formatting (no functional change)
[CHANGELOG] Changes for 0.1.3, 0.1.4