title: Multiple publications and subscriptions
body: <p>i have a problem with my meteor js implementation. The application has one collection named "tasks". I have in multiple places in my application many diffrent filters on this collection. In many cases i load diffrent lists with diffrent find queries in the same screen by using the same tasks collection. </p>
  
  <p>I wanted to use the publication-subscription model. Im not sure if im mistaken but is it the case that i cannot have multiple publications and subscriptions against the same mongo collection? 
  Specifically i use</p>
  
  <pre><code>Tasks= new Meteor.Collection("tasks");
  //server
  Meteor.publish('Tasks1',function(evalstring){return eval(evalstring);})
  
  Meteor.publish('Tasks1',function(evalstring){return eval(evalstring);})
  //client
  evalstring="Tasks.find({enabled:false}).fetch()";
  Meteor.subscribe('Tasks1',evalstring);
  </code></pre>
  
  <p>Would something like that work? If yes do we actually earn something in performance compared to the other way not using publications and running directly the find queries?
  Thanks</p>