Restore WifiHelper::SetStandard (WifiPhyStandard) with deprecated method
Recent changes to wifi removed (rather than deprecated) a WifiHelper method that is present in almost all wifi programs: WifiHelper::SetStandard (WifiPhyStandard).
It should be easy to keep this as a deprecated method for a release cycle or two and avoid compilation errors that may be hard for new users to track down.
- Tom