Support escaped spaces in filenames.

[youhavethewrong]

This should fix issue #287

[fabricereix]

sorry @youhavethewrong, can you rebase onto master?
thanks

I'm not sure whether all this new escaping should be done in the reader or not. This might be specific to the filename.
We can merge like that for the next release and maybe re-organize the code later one.
Parsing the filename, if it becomes more complicated shoudl probably have its own module/source file.

[youhavethewrong]

I agree, it's not ideal to have to update the reader. I've rebased as requested. Thank you!