times: Export & document countLeapYears/Years/Days
times: Export & document countLeapYears/Years/Days

Previously countYears & countDays procs were not public, but there were unused,
causing unnecessary warnings generated by standard library.

Since these procs seems to be useful it is better to just export them than
remove them completely. Also turning inline comments into proper documentation.

greyanubis/Nim,nanoant/Nim,Senketsu/Nim,Salafit/Nim,Dhertz/Nim,Senketsu/Nim,singularperturbation/Nim,Dhertz/Nim,tmm1/Nim,sarvex/Nim-lang,bvssvni/Nim,Senketsu/Nim,zachaysan/Nim,Salafit/Nim,Senketsu/Nim,bvssvni/Nim,haiodo/Nim,Dhertz/Nim,tulayang/Nim,sarvex/Nim-lang,Salafit/Nim,tmm1/Nim,jsanjuas/Nim,mbaulch/Nim,sarvex/Nim-lang,jfhg/Nim,zachaysan/Nim,zachaysan/Nim,Matt14916/Nim,jfhg/Nim,msmith491/Nim,dom96/Nim,Salafit/Nim,russpowers/Nim,nanoant/Nim,zachaysan/Nim,Matt14916/Nim,greyanubis/Nim,Salafit/Nim,msmith491/Nim,endragor/Nim,jfhg/Nim,russpowers/Nim,Matt14916/Nim,tulayang/Nim,msmith491/Nim,singularperturbation/Nim,jfhg/Nim,Salafit/Nim,Matt14916/Nim,Dhertz/Nim,nafsaka/Nim,endragor/Nim,Matt14916/Nim,endragor/Nim,dom96/Nim,tmm1/Nim,mbaulch/Nim,nanoant/Nim,tmm1/Nim,singularperturbation/Nim,nafsaka/Nim,greyanubis/Nim,Dhertz/Nim,jsanjuas/Nim,dom96/Nim,Senketsu/Nim,zachaysan/Nim,russpowers/Nim,jfhg/Nim,tulayang/Nim,zachaysan/Nim,endragor/Nim,haiodo/Nim,tulayang/Nim,Salafit/Nim,jsanjuas/Nim,jsanjuas/Nim,jsanjuas/Nim,Dhertz/Nim,tmm1/Nim,jsanjuas/Nim,msmith491/Nim,nafsaka/Nim,bvssvni/Nim,russpowers/Nim,msmith491/Nim,singularperturbation/Nim,singularperturbation/Nim,haiodo/Nim,Senketsu/Nim,msmith491/Nim,dom96/Nim,nanoant/Nim,greyanubis/Nim,nafsaka/Nim,endragor/Nim,sarvex/Nim-lang,sarvex/Nim-lang,tulayang/Nim,jfhg/Nim,singularperturbation/Nim,mbaulch/Nim,nafsaka/Nim,sarvex/Nim-lang,mbaulch/Nim,mbaulch/Nim,haiodo/Nim,Dhertz/Nim,jfhg/Nim,dom96/Nim,russpowers/Nim,mbaulch/Nim,bvssvni/Nim,tmm1/Nim,haiodo/Nim,singularperturbation/Nim,nanoant/Nim,mbaulch/Nim,bvssvni/Nim,jsanjuas/Nim,Matt14916/Nim,endragor/Nim,dom96/Nim,haiodo/Nim,Senketsu/Nim,greyanubis/Nim,nanoant/Nim,endragor/Nim,sarvex/Nim-lang,msmith491/Nim,zachaysan/Nim,nafsaka/Nim,tulayang/Nim,greyanubis/Nim,russpowers/Nim,haiodo/Nim,tmm1/Nim,bvssvni/Nim,greyanubis/Nim,nafsaka/Nim,bvssvni/Nim,Matt14916/Nim,dom96/Nim,russpowers/Nim,nanoant/Nim