~ruther/nix-fpga

ref: 9c69358f0f86b89e5cb4e5132b221538d738baae 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