adding etcd storage support for cluster meta data. Currently just

sequence. More to come...

go/sequence/memory_sequencer.go

@@ -0,0 +1,19 @@
+package sequence
+
+import ()
+
+// just for testing
+type MemorySequencer struct {
+	counter uint64
+}
+
+func NewMemorySequencer() (m *MemorySequencer) {
+	m = &MemorySequencer{counter: 1}
+	return
+}
+
+func (m *MemorySequencer) NextFileId(count int) (uint64, int) {
+	ret := m.counter
+	m.counter += uint64(count)
+	return ret, count
+}