xkcd Make-Out Spot

xkcd #201 in app form!

Randall Munroe's xkcd #201 suggests "Let's take our latitude & longitude, put our birthdays after the decimal points, then go to that spot and make out." Clearly, the world needs this as an Android app.

Change history:

- Respect local date format.

- Add alternate spots in case the originals are not reachable (over water, etc). Uses "ceil(lat,lon)-birthdays" as opposed to the normal "floor(lat,lon)+birthdays".

- Remember birthdays across app restarts.