Multi-level loading working.
Merge branch 'develop' of git+ssh://github.com/mousebird/WhirlyGlobe into develop
Merge fixed
Fixed globe related loading bug.
First cut at frame loading
Merge branch 'develop' of https://github.com/mousebird/WhirlyGlobe into develop
Differentiating between single level loading and multi-level loading.
Merge branch 'develop' of https://github.com/mousebird/WhirlyGlobe into develop
Integration with offline layer.