Changes since tag v3.1.12

commit 2511f9f66d8b1d13b1722b4396ffe9ee33c72d75
Author: Hendrik Leppkes <h.leppkes@gmail.com>
Date:   Tue Mar 14 13:06:42 2017 +0100

    Update toc for 7.1

commit 1c28940dead2bc730b5585170be1e9e6cd512e0d
Author: Hendrik Leppkes <h.leppkes@gmail.com>
Date:   Tue Mar 14 13:06:07 2017 +0100

    Simplify tank check to be based on current spec

