Add support for using the storage root in FileStream::.ctor.
Add support for using the storage root in FileStream::.ctor.

x335/JSIL,mispy/JSIL,hach-que/JSIL,Trattpingvin/JSIL,FUSEEProjectTeam/JSIL,sander-git/JSIL,acourtney2015/JSIL,volkd/JSIL,iskiselev/JSIL,FUSEEProjectTeam/JSIL,Trattpingvin/JSIL,FUSEEProjectTeam/JSIL,hach-que/JSIL,antiufo/JSIL,hach-que/JSIL,iskiselev/JSIL,acourtney2015/JSIL,sq/JSIL,hach-que/JSIL,x335/JSIL,TukekeSoft/JSIL,Trattpingvin/JSIL,TukekeSoft/JSIL,acourtney2015/JSIL,acourtney2015/JSIL,volkd/JSIL,iskiselev/JSIL,mispy/JSIL,mispy/JSIL,sander-git/JSIL,dmirmilshteyn/JSIL,sq/JSIL,antiufo/JSIL,volkd/JSIL,sander-git/JSIL,TukekeSoft/JSIL,FUSEEProjectTeam/JSIL,FUSEEProjectTeam/JSIL,antiufo/JSIL,volkd/JSIL,x335/JSIL,hach-que/JSIL,Trattpingvin/JSIL,mispy/JSIL,volkd/JSIL,sander-git/JSIL,x335/JSIL,iskiselev/JSIL,iskiselev/JSIL,dmirmilshteyn/JSIL,dmirmilshteyn/JSIL,acourtney2015/JSIL,sander-git/JSIL,dmirmilshteyn/JSIL,sq/JSIL,sq/JSIL,antiufo/JSIL,sq/JSIL,TukekeSoft/JSIL