MultiResolutionRenderer: actually use pre-allocated mask arrays...
pass re-usable ExecutorService to AccumulateProjector, and fix min/max bug
in calcuation of numTasks.
let ViewerImgLoader compute the mipmapTransforms.
Utility method for computing mipmapTransform (for standard averaging down-scaling)
move loadTimepoint() up to AbstractSpimSource. requires introduction of
abstract getImage() and getMipmapTransforms() methods which are implemented
to forward to ViewerImgLoader.
bufix in logic to reallocate renderImages (happened too often)