Overhaul of file deployment in dev mode and production mode

[tsevasa]

Please test this with DEV_BUILD turned on and off, respectively. It works perfectly fine for me.

[tsevasa]

ToDos:

• Currently, the copy method copies over many unnecessary game scripts to dist that are never loaded into an HTML. Although it doesn't matter, we should only copy what is necessary.
• Revert bundling for development mode.

[Naviary2]

Looking great! It's very fast for me too! 👏 (and it works in both dev and production for me)

I fixed this error! The validation script is not directly part of the game code.

Basically what's left is (and I'm sort of re-iterating what you already put) is to

• In production, skip copying over the game code to dist (except for concatenating app.js).
• In dev, skip concatenating app.js. (We can create a new module "HTMLPreparator" that will inject the script tags we need into play.html's header, depending on if we're in dev or production.

[tsevasa]

The TODO list is finished! In dev mode, now all assets and scripts are just copied over to dist. In prod mode, the scripts are concatenated into app.js (where applicable), and minified.

Finally, the play.html page, now does not call any game scripts by itself anymore. Instead, HTMLScriptInjector.js automatically recognizes the contents of dist/scripts/game and adds the appropriate script calls to the HTML file.