WIP: Break out Gruntfile into separate distinct tasks

Hi @f, I've been starting to work on DeLorean.  I have a few ideas I'd like to tackle:

- [X] Migrate Grunt tasks into separate files for better maintainability.
- [X] Fix JSCS and JSHint errors.
- [ ] Convert to ES6,
- [ ] Create distribution using the ES6 Module Transpiler.
- [ ] Load modules in tests using ES6 Module Loader.
- [ ] Convert to JSDoc and generate documentation.
- [ ] Remove `dist` folder, since you don't typically want to commit built files.