Begin using the LESS CSS preprocessor, and move stylesheets to /client/styles
Update README.md to mention grunt dependency
Start breaking up styles into separate files

** NOTE: This commit breaks Bootstrap icons (glyphicons). However, I'm planning on adding /client/vendor to the repo, after which I will update the paths to get the icons working again. I will do that in a separate commit.

Note also this breaks the quiz sidebar, but technically, it was already broken - will fix later.
Add /client/vendor to the repo

I was against doing this initially since this really bloats the size of the repository. However, there are significant advantages here:

- I can now override things much easier in the frontend packages.

- For example, I can go in and tweak Bootstrap styles (e.g., change the default font size) without having to do so in a separate stylesheet. Also, now that I'm using LESS, I more or less *have* to do this because the font path (@icon-font-path in variables.less) is wrong.

- Also, I can do things like add ckeditor plugins without having to copy them over in the prepublish.js script (like I'm currently doing).

- I can get rid of the 'bower install' command from prepublish (this has been giving me some trouble).

- Finally, adding frontend dependencies to the repo is generally considered a good idea since it locks all the dependencies to one specific version (similar to npm shrinkwrap, except bower doesn't have a shrinkwrap equivalent... all the more reason to go this route).
Get rid of the prepublish.js script, as well as bower.json

These are no longer needed now since I added all the bower-installed components to the repo directly
Fix bootstrap font path
Fix take quiz layout so that it's more responsive

The navigation sidebar is currently being hidden on mobile/tablet views - I'll need to come up with another approach here.