make map cursor "pointer" not "grab"
make map cursor "pointer" not "grab"

since:

- you can basically click anywhere now
- the particular way I'm using leaflet might not have a way to
    have different cursors in different places
- yes, you can still drag the map around. Luckily cursor:pointer
    still looks a lot like a hand like cursor:grab does, ish.
    And google maps lets you drag when you have your mouse over
    a marker such that the cursor pic is pointer.
    So hopefully that behavior is familiar.

This feels less confusing to me than clicking while
the cursor is "grab".

mbta-bus-app2/mbta-bus-app2.github.io,mbta-bus-app2/mbta-bus-app2.github.io,mbta-bus-app2/mbta-bus-app2.github.io,mbta-bus-app2/mbta-bus-app2.github.io