Awood/guard

* Add LiveReload functionality to give realtime previews when editing pages. 
* Update to Jekyll 2.0
* Do not deploy unnecessary *.less files.

From the README:

1. If you wish to see real time previews of your updates (i.e. if you don't want to hit the refresh button all the time), then you can use `bin/site-tool serve`.  This command is a wrapper around Jekyll but uses the [LiveReload protocol](http://feedback.livereload.com/knowledgebase/articles/86174-livereload-protocol) with a tool called [Guard](https://github.com/guard/guard).  Guard is very powerful and I recommend reading the documentation, but all you really need to know to get started is that you exit Guard by hitting Ctrl-D or by typing "e" or "exit".

   Guard will print some output and you should see a notice that Jekyll is serving on port 4000 and that LiveReload is waiting for a browser to connect.  Go to http://localhost:4000 and visit a page.  When you edit that page's source Markdown file and save, Guard will see the file modification and trigger a site build.  LiveReload will then refresh your browser for you if your browser is connected.  Sometimes it is a bit tricky to get the browser to make the initial WebSockets connection.  You may have to refresh or shift-refresh a few times.  You're connected when you see the "Browser connected" message on the Guard console.

1. **Extreme ProTip**: Unfortunately, Jekyll is a bit simplistic in how it  regenerates sites.  It regenerates everything instead of just what it needs to (improving this is on the roadmap for Jekyll 2.0).  I find waiting for the entire site to render to be tedious, so there is a faster way to preview changes if you're only working on a few pages:

 ```
   $ bin/site-tool isolate path/to/source/file.md
   ```
Using `isolate` will only render and serve the files you give as arguments plus a few other dependencies like CSS files.  You can provide as many source files as you like if you're working with more than one pages at a time.  The isolate command works by telling Jekyll to ignore everything but the files you specify.  The isolate command also includes the LiveReload functionality.