Prevent BlobItemContainer from receiving focus.

This seems to fix https://code.google.com/p/camlistore/issues/detail?id=183.
I could not find the code that is actually causing scrolling to occur ... I am
guessing something in Closure somewhere.

However, I also couldn't think of any reason for this component to be
focusable, and this doesn't seem to break anything that I can see.

Change-Id: Iaf64555ee175c774a218bb32d9bb4f97f46cc636

server/camlistored/ui/blob_item_container.js

@@ -54,6 +54,8 @@ camlistore.BlobItemContainer = function(connection, opt_domHelper) {
    * @private
    */
   this.eh_ = new goog.events.EventHandler(this);
+
+  this.setFocusable(false);
 };
 goog.inherits(camlistore.BlobItemContainer, goog.ui.Container);