AMD compatibility + some build tweaks

[benweet]

That's what I had to do to have it working with StackEdit:

• Added the whole build folder in the repository. The reason is that I use bower to manage this dependency, and I only want to include diagram-grammar.js and sequence-diagram.js in my project.
• Fixed the AMD incompatibility issue. Raphael is not defined globally when AMD is enabled.
• Specified jison version in readme.md, as the latest version of jison is not compatible.

[bramp]

Thanks @benweet for this work. Sorry for not reviewing sooner! I've made some changes which has broken this pull request.

However, I have some questions/comments

1. I've pinned the jison version to the latest now (via the package.json)

2. I'm unsure of the use case you describe only needing diagram-grammar.js and sequence-diagram.js, and I might have inadvertently broken that as I changed how the final file is built. Could you expand more why you would need this? I consider these files temp files that I don't want checked in.

3. I would be very happy to include the AMD improvements, but again my changes might have broken this. I personally don't use AMD, but I might investigate and add myself if you no longer have time.