add state to plans.Plan

Since the refreshed state is now an artifact of the plan process, it
makes sense to add it to the Plan type, rather than adding an additional
return value to the Context.Plan method.

plans/plan.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/hashicorp/terraform/addrs"
 	"github.com/hashicorp/terraform/configs/configschema"
+	"github.com/hashicorp/terraform/states"
 	"github.com/zclconf/go-cty/cty"
 )
 
@@ -16,15 +17,16 @@ import (
 // result that will be completed during apply by resolving any values that
 // cannot be predicted.
 //
-// A plan must always be accompanied by the state and configuration it was
-// built from, since the plan does not itself include all of the information
-// required to make the changes indicated.
+// A plan must always be accompanied by the configuration it was built from,
+// since the plan does not itself include all of the information required to
+// make the changes indicated.
 type Plan struct {
 	VariableValues  map[string]DynamicValue
 	Changes         *Changes
 	TargetAddrs     []addrs.Targetable
 	ProviderSHA256s map[string][]byte
 	Backend         Backend
+	State           *states.State
 }
 
 // Backend represents the backend-related configuration and other data as it