Properly license this work

[neiser]

We should license this software properly.

• Check requirements from third party
• Choose license consistent with university (should be open source)
• Check https://github.com/A2-Collaboration-dev/ant/community

This would enable automatic coverity checks (it's already prepared, but was rejected due to missing license).

[a2wagner]

The third party requirements are very permissive. Easylogging++ and TCLAP both use the MIT (or X11) license, cereal uses the BSD-3-Clause (pretty similar to the MIT one), and Catch uses the Boost Software License (BSL). They're all compatible with the GPL.

From the licenses of the third party projects which are used within Ant, MIT or GPLv3 should be good to go. Both are widely used Open Source licenses.