Refactor Scribl to an npm module

[multimeric]

Warning, this is quite a large PR:

• Rewrote javascript into roughly ES2015 level JS
• Used import and export statements to structure the library
• Added webpack settings for compiling the library into UMD
• Added package.json with relevant metadata for NPM publishing
• Removed the libs copied from Dalliance, and instead added them as npm dependencies
• Removed the implicit dependency on jQuery for event handling
• Fixed some serious code issues (using global variables, among other things)
• Added a new development section to the readme
• Removed the use of a custom Class construct, and instead used ES2015 classes and inheritance
• Fixed some minor JSdoc issues (such as the use of Int and Float instead of number)
• Minor style changes (mostly fixing indentation)

[multimeric]

I've tested the examples html files, which all work fine. However I'm leaving this as a draft until I have checked that this works correctly when it's imported as a module (as opposed to being used in the global scope, which the examples do)

[multimeric]

I ended up writing my own visualisation library for this, but I still did a heap of work refactoring Scribl so it might be useful to merge this, if you get a chance to review the massive amount of changes.

From my brief testing, it works for all the examples that worked in the original Scribl, and it worked in my React.js tests as well. I can't tell if I haven't broken some edge case, however, because there isn't a unit testing suite.

[chmille4]

I will try to review and merge though it will probably take me some time. Thank for this.

[multimeric]

Great, let me know if you have any questions about the changes I've made.