removing connection data from the providers

Very few resources need connection info, and rather than relying on
providers to set default for some resources, we are going to require
that connection blocks be explicitly set in the configuration.

providers/provider.go

@@ -243,10 +243,6 @@ type ApplyResourceChangeResponse struct {
 	// known state of the resource, if it exists.
 	NewState cty.Value
 
-	// Connection is used to return any information provisioners might require
-	// to cty.Value
-	Connection cty.Value
-
 	// Private is an opaque blob that will be stored in state along with the
 	// resource. It is intended only for interpretation by the provider itself.
 	Private []byte