text/template: rename the method Template.Template to Template.Lookup
Calling it Template makes it clumsy to embed the type, which html/template
depends on.

R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/5432079
diff --git a/src/pkg/text/template/exec_test.go b/src/pkg/text/template/exec_test.go
index 1cfa0d1..cf3c415 100644
--- a/src/pkg/text/template/exec_test.go
+++ b/src/pkg/text/template/exec_test.go
@@ -677,7 +677,7 @@
 	}
 	const expect = "[1[2[3[4]][5[6]]][7[8[9]][10[11]]]]"
 	// First by looking up the template.
-	err = tmpl.Template("tree").Execute(&b, tree)
+	err = tmpl.Lookup("tree").Execute(&b, tree)
 	if err != nil {
 		t.Fatal("exec error:", err)
 	}