Don't include the Buffer polyfill in dist/ files.

[dduponchel]

In a browser, there are multiple implementations of nodejs' Buffer. If we let browserify includes its own, we won't play nicely with the others (it uses instanceof and doesn't accept other implementations).
With this patch, we don't include any implementation but we let the environment provides (or not) the Buffer.

This pull request includes #140 (fixing #139 too) and the fix I prepared. I got no response from @humphd so I assume he's ok with it :)

[humphd]

Ah, lost this in my inbox while on holidays. I'll test your patch and make sure it works for my case. Thanks for this, I'll reply again soon.

[Stuk]

Looks good.

The nodeBuffer.js and nodeBufferReader.js files are included in the bundle after this PR. Is that intended?

[dduponchel]

I'll add the files in the ignore option. The difference in the generated file is quite small :

// with the nodeBuffer*.js files
File dist/jszip.min.js created: 286.65 kB → 75.23 kB → 16.5 kB (gzip)
// without them
File dist/jszip.min.js created: 285.83 kB → 74.74 kB → 16.47 kB (gzip)

[Stuk]

Yeah, not a size issue, just wanted to make sure it wasn't going to have some unintended consequences.

[dduponchel]

I am wondering if we should keep these files in the browserify bundle. In a browser with a Buffer shim, the new check (support.nodebuffer = typeof Buffer !== "undefined") will be true and JSZip will need these files.

[dduponchel]

I tested with a Buffer shim (a standalone browserify build of https://github.com/feross/buffer) :

• without these files, I get a lot of nodeBuffer.test is not a function errors
• with these files, the unit tests pass (and JSZip.support.nodebuffer is true)

I'll remove the last commit :)
edit : done