Include third-party hosted JavaScript

[SammysHP]

For two reasons:

• I like self-contained projects, which do not depend on the reliability of other services
• I am a NoScript user and have not whitelisted CDNs like CloudFront.

The drawback is a small increase in download size, but that shouldn't make a big difference, especially compared to other websites which are usually much bigger.

[niklashigi]

@SammysHP I would suggest using a dependency manager like Bower then. This would allow us to manage and update these dependencies without a lot of effort.