directory structure change to work with glide

glide has its own requirements. My previous workaround caused me some
code checkin errors. Need to fix this.

weed/stats/memory.go

@@ -0,0 +1,28 @@
+package stats
+
+import (
+	"runtime"
+)
+
+type MemStatus struct {
+	Goroutines int
+	All        uint64
+	Used       uint64
+	Free       uint64
+	Self       uint64
+	Heap       uint64
+	Stack      uint64
+}
+
+func MemStat() MemStatus {
+	mem := MemStatus{}
+	mem.Goroutines = runtime.NumGoroutine()
+	memStat := new(runtime.MemStats)
+	runtime.ReadMemStats(memStat)
+	mem.Self = memStat.Alloc
+	mem.Heap = memStat.HeapAlloc
+	mem.Stack = memStat.StackInuse
+
+	mem.fillInStatus()
+	return mem
+}