List on touch screen selects item on panning

ListView/TreeView should distinguish between touching the screen in order to scroll and touching the screen in order to select an item. Currently it always selects an item immediately on screen press. The negative effect can be well observed in Ensemble - when you try to pan the tree, an item is selected (with a possible subtree expansion) and the new sample is loaded, which is upsetting because you just wanted to scroll. I think we need a logic for touch screen that selects an item only on tap, not on scrolling.