Fixed a couple of compile errors for Xcode6.  Found a thread problem in the offline layer (was crashing).
Was reporting out of bounds coordinates for tap (wrapping around the world, basically)
Merge
Merge
Dealing with both directions in wrapping now.
Merge branch 'develop_2_3_1' into develop
Fix in comment
Selection working again for screen markers and labels.  Can now deal with new shader based approach.
Fixed flipped Y in layout manager.
Fixed a thread problem in offline layer.
Merge branch 'develop' of https://github.com/mousebird/WhirlyGlobe into develop
Found the ghost image problem in multi-frame loading case.
Offline renderer now operating on a frame at a time.
Found problem with initial view state missing when the layer is first enabled.  Found problem with frame priority switches confusing the quad layer.
Multiplex tile source wasn't accounting for frames correctly.  Dynamic drawable atlas now setting texture correctly at creation of drawables rather than waiting for someone else to do it.  Quad display layer tracking frames a little more closely.  Offline renderer now calculating image size based on what's loaded rather than frame 0.
Markers weren't being deleted from layout.
Tweaked the generated texture for thinner lines.
Messing with line widths
Wasn't checking if we used layout before removing screen objects from layout.  This speeds up certain cases.
Non power of 2 textures sizes made some devices unhappy.