Boris Feld <boris.feld@octobus.net> [Sun, 08 Oct 2017 20:37:13 +0200] rev 34826
configitems: register the full 'merge-tools' config and sub-options
We register the merge-tools config section (which has an arbitrary base config
value) and the possible sub-attribute. The sub-attribute has to be registered
first or at the same time otherwise the '.*' item would shadow them.
Merge tools could include "." in their name so we can't constrain any more
than just ".*".