Rebase to current version of the official repository

The first version of the patch was written based on revision 1099 of the official mercurial repository. A rebase to the hg-rev. 1142 (git-rev. 37460a15; of 2018-01-18) seems to work and is the current dev branch and branch patch_rebase_rev_37460a15. However: The code should be rebased to the current version of etherlab to incorporate further bug fixes etc. Test branches for this are e.g. patch_rebase_rev_10434f0c for a rebase to the corresponding commit 10434f0c of the gitlab repo. They do not work yet due to the major changes performed in the official repo.