Upload files [$50]

[mikeumus]

A file manager and the ability to upload files.
See mentions of "File" in the source:
https://github.com/webwrite/inlinegui/search?p=1&q=file&ref=cmdform

https://trello.com/c/kzNOlU23

--- There is a **[$50 open bounty](https://www.bountysource.com/issues/2567662-upload-files?utm_campaign=plugin&utm_content=tracker%2F1083298&utm_medium=issues&utm_source=github)** on this issue. Add to the bounty at [Bountysource](https://www.bountysource.com/?utm_campaign=plugin&utm_content=tracker%2F1083298&utm_medium=issues&utm_source=github).

[AJ0070]

@mikeumus is this still available?

[god160]

I'll implement this. PR coming shortly.