run: Ctrl+C works and gets passed to guest... at last!

readme: document graphics failures on arm and aarch64 further.

run

@@ -184,6 +184,7 @@ ${debug_vm} \
 '${buildroot_out_dir}/host/usr/bin/qemu-system-${arch}' \\
 -gdb tcp::1234 \\
 -m '${memory}' \\
+-serial mon:stdio \\
 -monitor telnet::45454,server,nowait \\
 -netdev user,hostfwd=tcp::45455-:45455,hostfwd=tcp::45456-:22,id=net0 \\
 -smp '${cpus}' \\
@@ -237,7 +238,6 @@ ${qemu_common} \
 -device rtl8139,netdev=net0 \\
 -dtb '${images_dir}/versatile-pb.dtb' \\
 -kernel '${images_dir}/zImage' \\
--serial stdio \\
 ${extra_flags} \
 "
     ;;
@@ -257,8 +257,6 @@ ${qemu_common} \
 -cpu cortex-a57 \\
 -device virtio-net-device,netdev=net0 \\
 -kernel '${images_dir}/Image' \\
--nographic \\
--serial stdio \\
 ${extra_flags} \
 "
     ;;