ENT:NetworkVar uses SetNW* instead of SetDT*

As far as my tests go, this breaks pretty much nothing.

Added an argument to ENT:GetNetworkVars to return entities, duplicator behaviour is still the same since it passes no arguments.

Also made the notify stuff work for both state.

Thirdperson mode and camera distance for vehicles now use NWVars instead of dtvars.

Vinh wanted to do this but I beat him to it, suck it.