title: Add UIProgressView for [PFObject pinInBackground] to monitor when pin is complete
body: <p>I think this is a fairly simple question...but we'll see about that.</p>
  
  <p>My setup:
  Xcode: 6.3.2; 
  Parse: 1.7.4; 
  Language: Obj-C</p>
  
  <p>I have a bunch of PFObjects that are displayed in a TableView and within each Cell there is a button that the use can tap to pin that individual PFObject to localDatastore, so if they were to lose WiFi later on he/she could still access that object and view its contents.</p>
  
  <p>What I would like to do is display a UIProgressView/UIProgressBar to monitor the progress of the object being pinned (some of my objects contain large files that may take up to 30 seconds to pin).  This way the user knows for sure that the object has been saved completely and there is smaller chance they will assume the object save immediately and turned off WiFi or something else happens to jeopardize his/her internet connection.</p>
  
  <p>Is there straightforward way to do this with Parse??</p>