~ruther/nix-fpga

ref: 63d383f79633efa8111c6032b2938f2417af66b9 nix-fpga/pkgs/xilinx/ise d---------
fix: ise udev
feat: add usb-driver to ISE
fix: ise udev
fix: update ISE udev rules
fix: require INSTALL_DIR only in final packages, not in shells
feat: add executables to fhs package, split to individual frameworks