Auto merge of #477 - redox-os:redox, r=SimonSapin
Auto merge of #477 - redox-os:redox, r=SimonSapin

Redox support

Redox uses `file:` at the beginning of any file paths. Therefore, a path like `file:///home/user/some%20file.txt` needs to turn into `file:/home/user/some file.txt`

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servo/rust-url,servo/rust-url