Linux support

[Artorp]

While the core file managing features works, there are still a few issues:

• [x] Application freeze on desktop browse
• [x] Superfluous junction check on non-Windows clutters log with stack trace
• [x] Better Factorio default location guessing
• [x] Exception when switching from symlink to rename and back
• [x] Activating a mod with valid Factorio installation doesn't enable launch button