Fully populate list on ExpBuilder load

[JayJohnsonWashoeCounty]

Idea: Add configuration option to the list widget to force full population of the list when ExpBuilder initially opens. 

When ExpBuilder opens, a list widget initially loads and displays only a subset of the features that should be in the list.  When the user picks a feature from a map, that feature gets highlighted and shows up in the list, but since not all features are initially displayed, that selected feature shows at the bottom of the list (ok), but none of the intervening features in the sorted list get populated yet.  So...if the user tries to click on the highlighted feature in the list, the highlighted feature gets PUSHED off of the display (seemingly disappearing), as more features (but still not ALL features) suddenly populate.

To further demonstrate the problem -- if, when ExpBuilder initally opens, the user manually scrolls to the bottom of the list, this forces the list to fully populate.  NOW, when the user clicks on the map, the feature is highlighted in both the map and the list and the list scrolls properly to show the feature in its proper place in the sort order.  User can click in the list and it operates as expected.