Decoupled map view with and without annotations, added tests.

[dblock]

This is prep work for #13, we want to simplify the map view and annotation interface, and give the annotation view to the annotation to deal with fully.

• Tests that load the various demo project items (menu, and each map) and compare snapshotted images of those. Uses https://github.com/dblock/ios-snapshot-test-case-expecta.
• Split NAMapView into an NAMapView and NAPinAnnotationMapView, we want pins to be a minimal interface that is basically a point and a view, and you can implement more complex scenarios like the one where a pin has a callout in subclasses. I am totally open for a discussion on what those base interfaces should look like - we can get this right now.
• Annotations mostly take care of themselves now. A lot of pin annotation logic has moved into the child NAPinAnnotation and NAPinAnnotationView.
• The interface around observing size changes is clearer, annotation views no longer have to observe size changes.
• Fixed iOS deprecation warnings.
• Wrote some README explanations on how to use NAMapKit.

[dblock]

cc: @orta and @robb, you guys know this codebase well, would appreciate a review of these, too

[orta]

terminology is a bit confusing here, plain & basic to me are pretty much the same.

[dblock]

I am renaming the first one to "NAAnnotation Demo" and the second one to "NAPinAnnotation Demo", which is what these are.

[neilang]

Thanks!