Start the merging-rebase to 0d438c7

This commit starts the rebase of 0d438c7 to 0d438c7

The idea is that this is the last merging-rebase before rebasing onto
v2.20.0-rc0. Read: no code changes, just rearranging the commits into
a nice, logical commit topology.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho