Investigate map click vs. pan

From @csmoore: "The only minor thing I noticed was-and this is probably just a problem with my particular mouse- if I clicked the map 50% of the time it registered as a 1-pixel map move/drag so the tap/single click didn't register. I tested again with the track pad and didn't have this issue so I can just blame my particular mouse. But I just mention this just in case this has been an issue before and there is some way to set the drag/map-move tolerance."