Phone call not quite working

Got the navigation to About view corrected again.

Put code in to make a phone call (my home number is in there for
testing) but when I run it on my phone, it’s not working yet.
Fix for non-responding telprompt:// link.  Hasn't been checked yet, since the iOS simulator won't do telephone calls (no phone app), and I can't try it on a real iPhone until I go to work.
Fixed the rotation/resize behavior of the GMSMapView; now when you rotate, the map will (eventually) conform to the new dimensions of the screen.
Fixed size/re-size issues with the UIWebView for the POI Details page

It's still not perfect, but I think it's mostly resolved
Added a filter item to remove the disc golf tee-box and basket icon markers from the map, while still leaving the hole polylines.
Added temporary POI icon for historical signs
Updated the project to include the Historical Sign icon
A few more fix-ups to prepare to merge Grace's one-touch-call feature
Merge branch 'grace/phone-calling'
Merge pull request #28 from agricocb/master

My last set of cleanup changes before the CS Fair presentation