Fix :h :{,tab,win}open argument specification.
Fix :h :{,tab,win}open argument specification.

Closes issue #136.

madand/pentadactyl-pm,nathyong/dactyl,invl/dactyl,Kjwon15/dactyl,airodactyl/dactyl,airodactyl/dactyl,Kjwon15/dactyl,madand/pentadactyl-pm,Kjwon15/dactyl,moonshadow/dactyl,madand/pentadactyl-pm,Kjwon15/dactyl,nathyong/dactyl,airodactyl/dactyl,nathyong/dactyl,airodactyl/dactyl,moonshadow/dactyl,moonshadow/dactyl,5digits/dactyl,5digits/dactyl,invl/dactyl,moonshadow/dactyl,moonshadow/dactyl,invl/dactyl,5digits/dactyl,airodactyl/dactyl,invl/dactyl,5digits/dactyl,madand/pentadactyl-pm,invl/dactyl,moonshadow/dactyl,nathyong/dactyl,Kjwon15/dactyl,nathyong/dactyl,madand/pentadactyl-pm,madand/pentadactyl-pm,nathyong/dactyl,5digits/dactyl,invl/dactyl,airodactyl/dactyl,5digits/dactyl,Kjwon15/dactyl