Added own directory in User config to where the
saved content is written and taken from, adapted
to also handle ExtensionConfiguration, changed
point for creating backups of configuration to
doShutdown, create no configuration when a restart
is triggered (untested configuration)

Change-Id: Id7a96195b765842c31cacf81cc08d2965a205281
Reviewed-on: https://gerrit.libreoffice.org/29729Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Armin Le Grand <Armin.Le.Grand@cib.de>