sliding view mouse latching

[hinathan]

On Safari 6 (10.8.1) as well as Chrome (haven't tried others yet)

http://triceam.github.com/app-UI/examples/samples/03%20-%20slidingView/01%20-%20basic/index.html

• Reload page
• Click, drag-to-expose-the-red-area
• With the mouse still down, move mouse outside of the window
• Return to the window (with mouse up or down)

Expected: Mouse-out-of-window or at least a followup click cancels moving the divider and leaves the page slidable again

Observed: Red-white divider continues to track the mouse once it returns to the window, and the original slide cannot be cancelled without refreshing the page.