First maintenance release

This is a maintenance release on top of v0.1. Major changes since the first release:

• Added a lot of documentation (see folder doc/hardware and doc/system)
• Describe a few additional test scenarios in TESTING.md, with a focus on networking tests
• Fixed DNS tests so that all networking tests complete again
• Fixed broken interrupt handling for AHCI drive on VirtualBox with ICH9
• Added a few new run targets in bin/run.sh
• Added new functions to CLI (host, http)

To run on Linux, extract the archive and type

./bin/run.sh

assuming that you have a working version of QEMU installed.