DefaultIndicatorPage: should use Loader status to determine the visible property

Here is the example code if somebody is interested in debugging the actual cause of this problem.

I would guess the Loader is getting confused as the Component it loads only defines implicitHeight initially.

Here is a screenshot what happens when "visible: height > 0"
http://imgur.com/v2juYHx

The red lines indicate the top and bottom of the first item and the red lines show them for the second item. It's clear from the picture that the items overlap inside the ListView.

This is how it should look like (and this is achieved by binding the visible property to the loader status):
http://imgur.com/VQD0jLj

And here is how I first noticed the problem:
http://imgur.com/bLui6FB

As you can see the the top most items overlap with each other. Interestingly having multiple items before the "Cellular Settings..." worked just fine:
http://imgur.com/XK0fEWt

And I also noticed that triggering this misalignment seems to be racy (19 times out of 20 the items was misaligned), but after applying the attached branch the problem could not be repduced anymore.

Oh, and just to clarify the bizarre nature of this bug it seems it only triggers when using the combination of ListView which has Loader as a delegate and the component given to it defines implicitHeight only and the component defines margins and it's implicitHeight depends on something like a label height. And this is exactly what happens when unity8 populates the indicator menus.

If the items are directly placed i.e. a Column or if the delegate is not a Loader or if the component does not define margins the bug does not manifest it self.

This bug was fixed in the package unity8 - 8.00+14.10.20140731.1-0ubuntu1

---------------
unity8 (8.00+14.10.20140731.1-0ubuntu1) utopic; urgency=low

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  [ Antti Kaijanmäki ]
  * DefaultIndicatorPage: use Loader status to determine the visible
    property. (LP: #1350555)
 -- Ubuntu daily release <email address hidden> Thu, 31 Jul 2014 16:51:01 +0000