Clarify replace(...)'s behavior on nil
Clarify replace(...)'s behavior on nil

mbaulch/Nim,endragor/Nim,fmamud/Nim,sarvex/Nim-lang,haiodo/Nim,mbaulch/Nim,msmith491/Nim,reactormonk/nim,Matt14916/Nim,Matt14916/Nim,nafsaka/Nim,Salafit/Nim,Salafit/Nim,JCavallo/Nim,sarvex/Nim-lang,mbaulch/Nim,fmamud/Nim,nanoant/Nim,bvssvni/Nim,JCavallo/Nim,JCavallo/Nim,russpowers/Nim,Dhertz/Nim,nanoant/Nim,jsanjuas/Nim,Matt14916/Nim,greyanubis/Nim,greyanubis/Nim,dom96/Nim,judofyr/Nim,jsanjuas/Nim,tmm1/Nim,fmamud/Nim,Dhertz/Nim,Senketsu/Nim,singularperturbation/Nim,fmamud/Nim,Salafit/Nim,Salafit/Nim,reactormonk/nim,endragor/Nim,nimLuckyBull/Nim,singularperturbation/Nim,haiodo/Nim,judofyr/Nim,douglas-larocca/Nim,msmith491/Nim,jsanjuas/Nim,xland/Nim,tmm1/Nim,sferik/Nim,xland/Nim,endragor/Nim,BlaXpirit/nre,jfhg/Nim,nanoant/Nim,russpowers/Nim,jsanjuas/Nim,msmith491/Nim,douglas-larocca/Nim,haiodo/Nim,bvssvni/Nim,tulayang/Nim,dom96/Nim,tmm1/Nim,flaviut/nre,nanoant/Nim,russpowers/Nim,Dhertz/Nim,jfhg/Nim,Senketsu/Nim,Dhertz/Nim,xland/Nim,greyanubis/Nim,msmith491/Nim,endragor/Nim,tmm1/Nim,judofyr/Nim,Senketsu/Nim,Matt14916/Nim,BlaXpirit/nre,singularperturbation/Nim,fredericksilva/Nim,tulayang/Nim,reactormonk/nim,Salafit/Nim,dom96/Nim,jsanjuas/Nim,Senketsu/Nim,russpowers/Nim,endragor/Nim,mbaulch/Nim,xland/Nim,xland/Nim,Senketsu/Nim,fredericksilva/Nim,bvssvni/Nim,xland/Nim,reactormonk/nim,Dhertz/Nim,nafsaka/Nim,fmamud/Nim,tulayang/Nim,sferik/Nim,fredericksilva/Nim,bvssvni/Nim,tmm1/Nim,sferik/Nim,Dhertz/Nim,msmith491/Nim,endragor/Nim,reactormonk/nim,JCavallo/Nim,fredericksilva/Nim,singularperturbation/Nim,sferik/Nim,haiodo/Nim,fredericksilva/Nim,jsanjuas/Nim,nafsaka/Nim,jfhg/Nim,jsanjuas/Nim,jfhg/Nim,dom96/Nim,nanoant/Nim,sferik/Nim,jfhg/Nim,singularperturbation/Nim,sferik/Nim,sarvex/Nim-lang,nanoant/Nim,nafsaka/Nim,fredericksilva/Nim,sferik/Nim,nanoant/Nim,judofyr/Nim,tmm1/Nim,xland/Nim,judofyr/Nim,Salafit/Nim,zachaysan/Nim,fredericksilva/Nim,haiodo/Nim,zachaysan/Nim,mbaulch/Nim,dom96/Nim,greyanubis/Nim,sarvex/Nim-lang,douglas-larocca/Nim,sferik/Nim,douglas-larocca/Nim,endragor/Nim,msmith491/Nim,sarvex/Nim-lang,bvssvni/Nim,jfhg/Nim,russpowers/Nim,greyanubis/Nim,tulayang/Nim,sarvex/Nim-lang,bvssvni/Nim,zachaysan/Nim,haiodo/Nim,Senketsu/Nim,mbaulch/Nim,jfhg/Nim,mbaulch/Nim,singularperturbation/Nim,Salafit/Nim,nimLuckyBull/Nim,Senketsu/Nim,singularperturbation/Nim,russpowers/Nim,judofyr/Nim,nafsaka/Nim,judofyr/Nim,tmm1/Nim,dom96/Nim,reactormonk/nim,fmamud/Nim,nimLuckyBull/Nim,bvssvni/Nim,nimLuckyBull/Nim,tulayang/Nim,greyanubis/Nim,Matt14916/Nim,dom96/Nim,nafsaka/Nim,douglas-larocca/Nim,Dhertz/Nim,Matt14916/Nim,JCavallo/Nim,reactormonk/nim,greyanubis/Nim,nafsaka/Nim,nimLuckyBull/Nim,douglas-larocca/Nim,nimLuckyBull/Nim,douglas-larocca/Nim,zachaysan/Nim,reactormonk/nim,Matt14916/Nim,msmith491/Nim,sarvex/Nim-lang,fmamud/Nim,JCavallo/Nim,russpowers/Nim,fredericksilva/Nim,tulayang/Nim,zachaysan/Nim,JCavallo/Nim,zachaysan/Nim,judofyr/Nim,nimLuckyBull/Nim,zachaysan/Nim,douglas-larocca/Nim,haiodo/Nim