Add directional current location icon

[nvkelso]

Paired up with mapzen/ios#333, add a new icon that shows both the current location dot ( • ) and adds a triangle that can orient towards direction of view, more like ( • )>

[nvkelso]

For v1 we'd need to whitespace buffer the non-triangle sides so the rotation point is
still centered on the ( • ) portion of the icon.

[msmollin]

We're looking at adding support for this as part of mapzen/ios#391 - did this get added yet?

[nvkelso]

It's not too hard to add, we can add it to the current icon sprint (for December release).