playground: Move v.io/x/ref/envvar files into v.io/x/ref

Fixes vanadium/issues#489

MultiPart: 3/3
Change-Id: I87d35b140c8b4f2e4436de59e96efe10990d8c52
diff --git a/go/src/v.io/x/playground/builder/main.go b/go/src/v.io/x/playground/builder/main.go
index 05fe76f..908d5c1 100644
--- a/go/src/v.io/x/playground/builder/main.go
+++ b/go/src/v.io/x/playground/builder/main.go
@@ -38,7 +38,7 @@
 
 	"v.io/x/playground/lib"
 	"v.io/x/playground/lib/event"
-	"v.io/x/ref/envvar"
+	"v.io/x/ref"
 )
 
 var (
@@ -396,7 +396,7 @@
 	cmd := exec.Command(progName, args...)
 	cmd.Env = os.Environ()
 	if credentials != "" {
-		cmd.Env = append(cmd.Env, fmt.Sprintf("%v=%s", envvar.Credentials, filepath.Join(credentialsDir, credentials)))
+		cmd.Env = append(cmd.Env, fmt.Sprintf("%v=%s", ref.EnvCredentials, filepath.Join(credentialsDir, credentials)))
 	}
 	stdout, stderr := lib.NewMultiWriter(), lib.NewMultiWriter()
 	prefix := ""
@@ -414,7 +414,7 @@
 func main() {
 	// Remove any association with other credentials, start from a clean
 	// slate.
-	envvar.ClearCredentials()
+	ref.EnvClearCredentials()
 	flag.Parse()
 
 	out = event.NewJsonSink(os.Stdout, !*verbose)
diff --git a/go/src/v.io/x/playground/builder/services.go b/go/src/v.io/x/playground/builder/services.go
index 187656d..156d7a1 100644
--- a/go/src/v.io/x/playground/builder/services.go
+++ b/go/src/v.io/x/playground/builder/services.go
@@ -19,7 +19,7 @@
 	"time"
 
 	"v.io/x/playground/lib"
-	"v.io/x/ref/envvar"
+	"v.io/x/ref"
 )
 
 var (
@@ -46,7 +46,7 @@
 	if endpoint == "" {
 		return nil, fmt.Errorf("Failed to get mounttable endpoint")
 	}
-	return cmd.Process, os.Setenv(envvar.NamespacePrefix, endpoint)
+	return cmd.Process, os.Setenv(ref.EnvNamespacePrefix, endpoint)
 }
 
 // startProxy starts a proxyd process.  We run one proxyd process for the