and flatten some data structures, no need to allocate some of the the
vector members on the heap

Change-Id: I8e7e06144da2fa58c8e3352013d44d368d61ea1d
Reviewed-on: https://gerrit.libreoffice.org/48480Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>