document new null-friendly functions
document new null-friendly functions

rogerz/jansson,bstarynk/jansson,bstarynk/jansson,Vorne/jansson,akheron/jansson,npmccallum/jansson,liu3tao/jansson,rogerz/jansson,npmccallum/jansson,chrullrich/jansson,OlehKulykov/jansson,rogerz/jansson,attie/jansson,wirebirdlabs/featherweight-jansson,akheron/jansson,AmesianX/jansson,wirebirdlabs/featherweight-jansson,rogerz/jansson,attie/jansson,Mephistophiles/jansson,firepick1/jansson,firepick1/jansson,slackner/jansson,AmesianX/jansson,liu3tao/jansson,Mephistophiles/jansson,Vorne/jansson,bstarynk/jansson,OlehKulykov/jansson,markalanj/jansson,firepick1/jansson,markalanj/jansson,markalanj/jansson,chrullrich/jansson,akheron/jansson,slackner/jansson