Allow partial without .html
Allow partial without .html

`partial "header" .` means the same thing as `partial "header.html" .`.

derekperkins/hugo,mdhender/hugo,fedelibre/hugo,abourget/hugo,fedelibre/hugo,ifraixedes/hugo,tubo028/hugo,mitchchn/hugo,ffrizzo/hugo,tjyang/hugo,Zenithar/hugo,tjyang/hugo,vbatoufflet/hugo,mitchchn/hugo,ffrizzo/hugo,bramp/hugo,fhergomez/hugo,sprig/hugo,fedelibre/hugo,gohugoio/hugo,digitalcraftsman/hugo,melo/hugo,vbatoufflet/hugo,sprig/hugo,mdhender/hugo,tischda/hugo,badoet/hugo,soundrussian/hugo,melo/hugo,tubo028/hugo,ryanclarke/hugo,fhergomez/hugo,ryanclarke/hugo,tatsushid/hugo,MarkDBlackwell/hugo,soundrussian/hugo,Zenithar/hugo,halostatue/hugo,tatsushid/hugo,kujohn/hugo,abourget/hugo,mayah/hugo,bogem/hugo,anthonyfok/hugo,mdhender/hugo,coderzh/hugo,jygastaud/hugo,MarkDBlackwell/hugo,halostatue/hugo,bogem/hugo,ifraixedes/hugo,bramp/hugo,fedelibre/hugo,kujohn/hugo,mayah/hugo,gohugoio/hugo,derekperkins/hugo,tischda/hugo,coderzh/hugo,anthonyfok/hugo,anthonyfok/hugo,digitalcraftsman/hugo,jygastaud/hugo,gohugoio/hugo,badoet/hugo,mdhender/hugo