Allow a tile cache to accept an NSData object directly instead of converting downloading tile data, converting to PNG then having the cache convert the PNG back to NSData for storage purposes (which is an expensive operation).  This was the steps the disk-based sqlite cache was performing.
Commented out some logging statements for now.
Switch to using NSImage throughout instead of using the "emulated" UIImage which was was Chameleon.  This appears to also have fixed crashing issue with zooming in/out on Mapview.