ipfs cmd help now shows update

+ reorder of plumbing

cmd/ipfs/ipfs.go

@@ -34,19 +34,22 @@ Basic commands:
 Tool commands:
 
     config        Manage configuration.
+    update        Download and apply go-ipfs updates.
     version       Show ipfs version information.
     commands      List all available commands.
 
-Plumbing commands:
-    block         Interact with raw blocks in the datastore
-    object        Interact with raw dag nodes
-
 Advanced Commands:
 
     mount         Mount an ipfs read-only mountpoint.
     serve         Serve an interface to ipfs.
     net-diag      Print network diagnostic
 
+Plumbing commands:
+
+    block         Interact with raw blocks in the datastore
+    object        Interact with raw dag nodes
+
+
 Use "ipfs help <command>" for more information about a command.
 `,
 	Run: ipfsCmd,