Add stats package and node related statistics model

stats/leveldb.go

@@ -0,0 +1,10 @@
+// Copyright (C) 2014 Jakob Borg and Contributors (see the CONTRIBUTORS file).
+// All rights reserved. Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+
+package stats
+
+// Same key space as files/leveldb.go keyType* constants
+const (
+	keyTypeNodeStatistic = iota + 30
+)