Loading arbitrary local JSON file

[ArtPoon]

JS makes this difficult because it leads to a vulnerability (see also issue #17). In the current branch fbc51c7, the input for specifying a file displays a dummy path:

$("#fil").val()
"C:\fakepath\projects.json"

On further inspection, this input is storing the file metadata in a less obvious location:

$("#fil")[0].files[0]
File(775706) {name: "projects.json", lastModified: 1532438548156, lastModifiedDate: Tue Jul 24 2018 09:22:28 GMT-0400 (Eastern Daylight Time), webkitRelativePath: "", size: 775706, …}

Check that this is the sanctioned approach to loading a local file.

[ArtPoon]

See also http://github.com/ArtPoon/pixelcraft for an example of using the JavaScript File API to enable users to upload local files.