this allows for easy cloning and build system maintenance also for
modules which are currently irrelevant, thus hopefully keeping the
barrier to their revival low. it does not affect the casual developer or
the CI system, as init-repository will not clone these modules.

This (abstractly) reverts commits
41c3f2cb,
725a51b1 and
1117d4da

.

Change-Id: Iabc750642fc1c163f3ebc96cf6edaa9b04378094
Reviewed-by: Sergio Ahumada <sergio.ahumada@digia.com>