Added membuffers tag

cloudcontrol/node/host/tags.py

@@ -83,6 +83,13 @@ def memused():
     return unicode(psutil.used_phymem())
 
 
+@ttl(5)
+@refresh(10)
+def membuffers():
+    """Buffers memory use."""
+    return unicode(psutil.phymem_buffers())
+
+
 # disks related tags
 def disk():
     """List of disk devices on the host."""