fix subgraph loading on windows
fix subgraph loading on windows

saurabhsood91/noflo,lxfschr/noflo,saurabhsood91/noflo,trustmaster/noflo,lxfschr/noflo,npmcomponent/noflo-noflo,jonnor/noflo,jonnor/noflo,noflo/noflo,trustmaster/noflo