Export and entry point

[lvenerosy]

This is a small PR to improve the experience of NPM users:

• the entry point has been moved from the browserified solver to the source code. This way it is possible to build (namely browserify) a project that uses the solver.
• @JWally I just erased the environment export system to replace it with a simple module.exports. I did that because of a bug I had after I browserified the solver and some code that need it, together. And then I load everything through an html page. So could you check if the simple export works with all the environment you want to support ?

@JWally last point, after this patch, could you update the version on NPM please ?

[JWally]

@lvenerosy when I include ./src/solver.js in a browser, I don't appear to have visibility to solver. Are you having success getting it in a browser? I haven't had my coffee yet, so I'm probably missing an obvious step somewhere 😜

Could you describe the issue you were having a little more?

Sorry I've been absent on this project for a while. I'll try and look at this some tonight (CST).

Thanks! -JWW

[lvenerosy]

I was a bit vague in my explanation but now the html include should work.