[TIMOB-6348] iOS: ProgressBar does not display correctly when 'top' is not set

For some reason, when the 'top' property is not set up a progress bar, the progress is always displayed as 100%. This was reported as a doc error, (TIMOB-5809) but I believe this part of the bug is an iOS bug. This behavior does not occur on Android. To reproduce, use the following code in app.js:

var win1 = Titanium.UI.createWindow({
	title : 'Progress Bar Test',
	backgroundColor : '#fff'
});

var pb = Titanium.UI.createProgressBar({
	// top: 10,
	width : 250,
	height : 50,
	min : 0,
	max : 10,
	value : 5,
	color : '#fff',
	message : 'Downloading 0 of 10',
	font : {
		fontSize : 14,
		fontWeight : 'bold'
	},
	style : Titanium.UI.iPhone.ProgressBarStyle.PLAIN,
});

win1.add(pb);
pb.show();
win1.open();

When run on iOS, the progress bar shows up as 100% done. If you uncomment the "top: 10" line and re-run, the progress bar shows up with the proper value--50% done.