Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option build-use-sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Fits CONTRIBUTING.md.

Not ready for merge! Some quirks to figure out first.

This commit adds build files for Cisco's Packet Tracer.

This builds and runs when declared in an overlay (via ~/.config/nixpkgs/overlays/), but when installed from this nixpkgs fork does not link against libQt5{Multimedia,PrintSupport,Svg,Widgets,Gui,Network,Xml,Core}.so.5 , which can all be found in qt56.full according to nix-locate. I request some help with this.

Other than that, the bin/meta binary depends on lib{icui18n,icuuc}.co.52, neither of which can be found by nix-locate. Should they perhaps be replaced with the libraries from icu59?

Some files fails to extract from the tarball, but these are but saves; they are not required to run the program.

Lastly, the program will complain and not use the extensions/upnp/upnp binary if patched. I suspect it's checked against some hash behind the scenes. (Not that the unpatched binary can be used anyway..) Any case, the program appears to function without it.