Only request tiles in image bounds.
Callback may want to set a call back.
Merge branch 'finished-loading'

* finished-loading:
  Callback may want to set a call back.
Fixed angle glitch for stack interpolation
Merge branch 'angle-glitch'

* angle-glitch:
  Fixed angle glitch for stack interpolation
Debug changes for stack crystal rendering.  Only annotation and eventually save when tiles are already loaded.
Merge branch 'mask-hack'

* mask-hack:
  Debug changes for stack crystal rendering.  Only annotation and eventually save when tiles are already loaded.
Copyright was messing up mask
Merge branch 'mask-hack2'

* mask-hack2:
  Copyright was messing up mask
Merge branch 'bounds'

* bounds:
  Only request tiles in image bounds.