Paragon NTFS

I tried to configure the `uninstall` setting, but when I tested `brew cask uninstall paragon-ntfs` something deleted a system file and I had to reinstall OSX.

The `pkg` value is `com.paragon-software.filesystems.NTFS.pkg` (run `pkgutil --volume / --pkgs | grep paragon` to confirm), but beware of hooking up the `uninstall` part of the Cask.