New logo and split of README in multiple pages

This is a cleanup and reorganization of the Infix documentation.
Starting with a simplification of the top-level README, splitting
it up into several pages.

Also, fixes #100 by updating the documentation on Qemu.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

doc/virtual.md

@@ -0,0 +1,57 @@
+Infix in Virtual Environments
+=============================
+
+Infix primarily targets real hardware, deployment to the cloud is not a
+priority at the moment.  However, for development and testing purposes
+there is an `x86_64` build that runs in [Qemu][].
+
+These images also work with the Graphical Network Simulator ([GNS3][]),
+which is a very user-friendly tool for playing around with simple to
+complex network setups, verifying interoperability between vendors, etc.
+
+
+QEMU
+----
+
+> **Note:** installation for Debian/Ubuntu based systems: <kbd>sudo apt
+> install virt-manager</kbd> -- dependencies ensure the relevant Qemu
+> packages are pulled in as well.  Installing [virt-manager][virt] helps
+> set up Qemu networking on your system.
+
+A virtualized Infix x86_64 instance can easily be launched from a Linux
+system, with [Qemu][] installed, by issuing:
+
+    ./qemu.sh
+
+from an unpacked [release tarball][rels].  From a built source tree of
+Infix the same functionality is bundled as:
+
+    make run
+
+To change settings, e.g. networking, <kbd>make run-menuconfig</kbd>, or
+from a pre-built Infix release tarball, using <kbd>./qemu.sh -c</kbd>
+
+The Infix test suite is built around Qemu and [Qeneth][qeth], see:
+
+ * [Testing](doc/testing.md)
+ * [Docker Image](test/docker/README.md)
+
+
+GNS3
+----
+
+Download the [latest build][rels] of the `x86_64`, or `x86_64_classic`
+flavor.  Unpack the tarball in a dedicated directory and use ["Import
+Appliance"][APPL] to install the `.gns3a` file into [GNS3][].
+
+Infix (`x86_64`) is in the "Router" category, it has with 10 interfaces
+available by default for use as switch ports or routing.  The *classic*
+build only has one interface by default, geared more towards acting as
+an end device.
+
+[Qemu]: https://www.qemu.org/
+[GNS3]: https://gns3.com/
+[virt]: https://virt-manager.org/
+[rels]; https://github.com/kernelkit/infix/releases
+[qeth]: https://github.com/wkz/qeneth
+[APPL]: https://docs.gns3.com/docs/using-gns3/beginners/import-gns3-appliance/