Another batch of commits working on the custom POI bubbles, POI icons, and APN support

Three items in this pull:
The custom pop-up bubbles for tapped POIs are coded, and they have the POI name along with one or two buttons.  One button is the "More info" button to launch the POI URL, and the other is the "Share" button, which is dynamically placed.  Once we have the config object to query to find out if we are logged in to a social media service, it can appear or not dependent on that.

The code to use custom POI icons based on the type value from the database table is in this pull, along with three stand-in icons that are eagerly waiting to be replaced with something that doesn't look like it was scribbled by a toddler.

And finally, the boilerplate code for enabling the APN push notifications is in.