GetNews view adds more articles when hitting search repeatedly

[gursi26]

As title says. To reproduce, do the following;

1. Go to the get news view
2. Enter a search term
3. Hit the search button multiple times

The number of articles increases without a reset.

[quiz3]

To resolve this, I believe I will need to modify the propertyChanged method of GetNewsView and make it so that the pane is reset each time the property changes in a way that would add more news.