title: max size in BlobProperty (appengine)
body: <p>What is the maximum size of one BlobProperty in appengine? 
  I'm not talking about of the Blobstore API, i'm referring to the property class <a href="http://code.google.com/appengine/docs/python/datastore/typesandpropertyclasses.html#BlobProperty" rel="noreferrer">BlobProperty</a></p>
  
  <p>Please add a link who support your answers </p>