Arguably should be the default. Implementation is a bit cute -
re-starting the main-loop as a child of a callback from its
idle handler.

Change-Id: I95e87c8a4ae3de745d7ca1f636859dd1d8deca17
Reviewed-on: https://gerrit.libreoffice.org/72070Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
Tested-by: Miklos Vajna <vmiklos@collabora.com>