Grunt build for Jia. Fix #125.

## Anticipated Questions

#### Did you check in the built assets?
No, I changed my mind and decided not to.

#### So if I want to run Jia at all, now I need Grunt?
Not if `DEBUG = True` in your settings file. All of the static files are in the same exact place as they were before. If you set `DEBUG = False`, it attempts to access the built assets though (which just make things more efficient).

#### What does the build process actually do?
* Concatenate all the templates for preloading.
* Concatenate all the js and css so that only one js file and one css file are loaded at run time rather than 20 of each.

#### Are there any more potential uses for the build process?
* Compiling Sass
* Minifying stuff
* Using non-minified 3rd party libraries in dev
* Running tests
* A handful of miscellaneous optimizations that are likely overkill at this point