Make sure sources listview column widths are as expected after obs window is shown
Merge pull request #70 from hwdro/master

Small fix for sources listview column widths not being initially resized.
Make sure when adding a new source that the list item coresponding to it is visible and selected (also deselect all previous selected items)
Merge pull request #71 from hwdro/master

Some 'quality of life' fix regarding sources list view