anchor.diff:  This <<flow,_flow_>> is running on a client because a user initiated it. To do
   so, he probably used the web-based Graphical User Interface (GUI), which allows
   a GRR user to start flows for clients and review the results. Or he could also
  -have used the text-based <<_the_console,_console_>> to do the same.
  +have used the text-based <<the-console,_console_>> to do the same.
   
   Any flow that can be run on a single machine can also be run as a Hunt. A hunt
   allows running a flow on all, or any subset of machines talking to the GRR
  
positive.code: 
  To function, an <<agent,_agent_>> is deployed on systems that one might want to
  investigate. Once deployed, each system becomes a GRR <<client,_client_>> and
  they can start receiving <<message,messages>> from the frontend servers. Each
  message tells the client to run a specific <<client_action,_client action_>> and
  return the results. A client action is simply some well known code the agent
  knows how to execute (such as obtaining the list of files in a directory or
  reading a buffer from a file).
  
negative.code: 
  We've seen how Flows were created through the UI. Now, we are gonna issue our
  own 'ListDirectory' flow, giving it parameters and then you can check the
  <<_available-flows,available flows>> list to decide what else you might want to
  run on your client.
  
  To start a new Flow simply click on the 'Start new flows' option on the left
  