New screen space calculations.  Working well with model matrix, but not full matrix yet.  Now requiring low level rendering objects to be named so I can trace them back to their origin.  Running all scene changes through the layer thread so we can flush them.  Added a dictionary for quad tree idents so developers can store their own data.  Textures now support 1 byte and 2 bytes formats.  A few more geometry utilities.
Selection delegate method now includes screen point.  Broke out the gl view setup.  Added attributes to pass around for tile loading.
Implemented dynamic texture atlases.  Cleaned up the layer add scene change logic.
Rebuilt WhirlyGlobeComponentTester project.  Instruments now works.
Drawable Atlas implemented, but not tested.
Triangle stripping now working.
Moved renderer into a dispatch queue.  This should fix scroll view interaction problems, but doesn't fix the 60/30 fps problem.  Now updating smaller portions of the dynamic buffers as needed.
Scaling skirts to tile size.  Compressed images won't work with dynamic atlases.  Turned them off.  Optimizing state changes in renderer.  Using VAOs for big drawables.
60hz sustained, after an initial startup period.  No idea why.
Fixed a draw priority problem.  Made async rendering optional.
Now explicitly tearing down opengl memory in case someone's keeping the context around.  Fixed a circular reference to the scene renderer.  Made more efficient use of the isReady option in the quad tile loader.  Tiles are loading more efficiently. Chunk layer updated to use atlases, but not entirely finished.  Moved quad tile loader over to using an more detailed definition of the images.  Allows for several types of data to be passed in, more to come.
Switched to a less intrusive locking model for dynamic drawable updates.
Finished up spherical chunk support for atlases.
Added mode where tilt is controlled by height above globe.  Finished new screen importance calculation.  Now mostly working.
Added a test layer for tracking down tile loading problems.  Finished up the screen importance calculation, seems to be tuned.
New bounding box calculation for vector object.  Added a few options to process dynamic texture and drawables updates on the main thread.  Started on 3D object selection in selection layer.
Now properly implemented the buffer switch in the dynamic drawables.  Got rid of the flickering.  Also now gating texture atlas frees based on the drawable switch.
Loft layer now allows for an explicit layering function.  This works well for large polygons that the vector filled option can't handle.  Added the buffer texel option in the loaded images.  Messing with the screen importance.  Turned off the buffer builder.
Border pixel support for texture atlases working.
Added Point3d (double) versions of the coordinate transforms.  Converted the screen space logic to doubles.  This fixes paging problems in the new screen space calculations.