simplify the initialisaion and make them thread-safe i.e. initialise
them using the runtime's local static locking.

Thanks to mike kaganski for pointing out the nice lambda approach that
makes this feasible.

Change-Id: I76391189a6d0a3d7eed2d0d88d28dfa6541eaff7
Reviewed-on: https://gerrit.libreoffice.org/63645
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>