Error on history.js

[amazeika]

History.js is throwing a JS error under some conditions.

History.unescapeString function keeps decoding URLs on a while block using window.decodeURI. This function throws an error if an invalid %xx URLencoded character is provided. This means that any folder with a %xx substring on it is likely to make it fail.

Steps to reproduce on FILEman:

1. Go to backend and create a %dabug directory.
2. Refresh the whole browser page.
3. Delete the folder.
4. Create the same folder.

You should get a Uncaught URIError: URI malformed error and the submit box doesn't get closed.