NeighborhoodOp: Added name
AbstractSlicer: "Better" error message
ImgSlicer: Remove ImgSlicer

ImgPlusSlicer also returns an Img. Open Problem:
The output of the slicer is an ImgPlus (which was automatically wrapped).
This may not be the desired behaviour.
Slicer: Added priority field in annotation
SlicerTests: Added Slicer-Tests
SliceIterableInterval: Fixed correct minimum
Merge branch 'master' of https://github.com/imagej/imagej-ops

Conflicts:
	src/main/java/imagej/ops/slicer/ImgSlicer.java