Add node server capability close #1

[DrewMcArthur]

This adds the possibility for running the server with the usage of node.js. Adds the app.js file (the server itself) and the package.json file, which manages dependencies. Getting the server running on a local machine is as easy as five lines in a Linux terminal. This is useful for people who want to set up the server on their own computer, to test changes to the code.

These changes shouldn't affect how the server is running currently, and therefore shouldn't have any effect on CoopGameMaking.com, however it will make the testing process easier for those familiar with node.

[DrewMcArthur]

There is an issue in that the save and load buttons don't work for server communication when being run by node. However, since this should be primarily used as a testing server, the issue isn't too important. When this gets merged, I'll add that as an issue that I can look into.

[ghost]

Don't you think express is a little too heavy for what is needed.

I find static-serve can do what we need and only has 4 package dependencies as opposed to express's 24 dependencies.

I don't know if you can have a pull request on top of a pull request, but I'd like to have a go at solving the Save/Load events on a Node server. At the same time I'd also like to use static-serve instead of express.

[DrewMcArthur]

I'm not all that knowledgeable with node, I just know that this works. If your PR is the better option in terms of usability, then I'll close this.