remove the option ref, add option ref.label (#58)
remove the option ref, add option ref.label (#58)

antass/labnotebook3,fboehm/cboettig_site,fboehm/cboettig_site,fboehm/labnotebook,fboehm/labnotebook,fboehm/cboettig_site,fboehm/cboettig_site,fboehm/labnotebook,fboehm/labnotebook,fboehm/cboettig_site,antass/labnotebook3,antass/labnotebook3,fboehm/labnotebook,fboehm/labnotebook