adding missing copyrights and excluding the bower_components directory

Still two rogue copyright errors. Not sure if things in `./dist/` should have copyright banners or not. Or, if we do need to add copyrights and the /dist/ folder is generated, we'd need a way to add copyrights automatically.

```
$ grunt copyright
Running "copyright:app" (copyright) task

The following files don't match the specified pattern:
> /This Source Code Form is subject to the terms of the Mozilla Public/

- dist/scripts/d41d8cd9.main.js
- dist/scripts/vendor/d41d8cd9.modernizr.js
Warning: Task "copyright:app" failed. Use --force to continue.

Aborted due to warnings.
```