files.json path separator

[an0nym05]

I've noticed that code generated under windows uses ""\" as path separator in files.json.
This returns error when trying to compile under OSX/Linux as "cannot find file bin\something".
The generator's code should take difference into account regardless the development platform.

[codablock]

I never tested building on Windows, as I'm only able to use Mac and Linux as built systems. I used cross-compilation to get Windows builds working.

If someone is able to provide fixes for Windows as build system, I'm happy to accept PRs.

[floriaanpost]

I have another MR (#52) that fixes this when generating. I think that might be a better solution (as the files.json will be consistent across operating systems)