Found a few issues with the zoom feature.

1. If highlighting on a building and you zoom in to where your cursor isn't on the building anymore, the label will stay until you move your mouse
2. When zooming, the map zooms towards the center of the map at all times (DCC). Should be changed so that it zooms towards your cursor.
3. Breaks the boundaries set for dragging the map around. When zooming in, the position at where you get pushed back towards the center by dragging around should stay the same.