Update bookmark and ahelp ids.
Removed sys=WIN marks because these informations are visible
on Linux too (no idea about Mac though).
Add documentation about the Options button.
Change-Id: Ia59119b266b4794655f7236622fc1c5c40b4095c
Reviewed-on: https://gerrit.libreoffice.org/31858
Reviewed-by: Olivier Hallot <olivier.hallot@edx.srv.br>
Tested-by: Olivier Hallot <olivier.hallot@edx.srv.br>