Restyle hover effect in nav bar

The nav bar hover effects weren't working, this commit ads custom effect
when you hover over items in the nav bar.

Also the menu icon was removed since the icon font isn't present yet.
Restyle zone and user pages

This commit adds some extra spacing on the individual zone and user
pages. It also now shows checkin lists in chronological order (most
recent first).

There's also a guard added so that if there are 0 checkins then the
table won't be shown.
Add zone list to area show page

This commit adds the zone list on the area show page. The zone list has
been extracted into a partial to keep things dry.

There was some other style changes done including a mobile enhancement
so that the map is more readable on a small screen.