Support `FileList` as input for the `seed` method

[valeriangalliat]

The W3C FileList object has no map method, thus it needs to be converted to an array before using.

Otherwise I got input.map is not a function with the following code:

var WebTorrent = require('webtorrent')

var client = new WebTorrent()

// `input` is a file input
input.onchange = function (e) {
  client.seed(e.target.files, function (torrent) {
    console.log('Torrent info hash:', torrent.infoHash)
  })
}

[feross]

Thanks for catching this. I never caught this because my drag-drop module returns a proper array, not a FileList. We need better browser tests to catch things like this going forward.

This is a good start, but it's also a partial fix because the lines that create the file buffer (https://github.com/feross/webtorrent/pull/153/files#diff-168726dbe96b3ce427e7fedce31bb0bcR208) will not access the file data from the FileList correctly. I'll fix this.

[feross]

@valeriangalliat Okay, you should now be able to seed a FileList correctly as of webtorrent 0.10.1.

[valeriangalliat]

Awesome, thank you!

[feross]

@valeriangalliat - sorry, there was a bug in 0.10.1. Give 0.10.2 a try!

[valeriangalliat]

No problem, I didn't have the time to try it yet. I'll give you feedback in the following days. :)