Upped the default number of vector tiles.
Merge branch 'develop' of https://github.com/mousebird/WhirlyGlobe into develop
Merge branch 'develop' of https://github.com/mousebird/WhirlyGlobe into develop
Merge branch 'develop' of https://github.com/mousebird/WhirlyGlobe into develop
Allowing coordinate display adapters to have separate centers.