Add IterableLoopBuilder

[maarzt]

It is similar to LoopBuilder but works with IterableInterval and RandomAccessible.

This should allow to simplify a lot of code in imglib2-algorithm as done in imglib/imglib2-algorithm#83.

IterableInterval<DoubleType> sum = ...
RandomAccessible<DoubleType> imageA = ...
RandomAccessible<DoubleType> imageB = ...
IterableLoopBuilder.setImages(sum, imageA, imageB).forEachPixel(
    (s, a, b) -> {
         s.setReal(a.getRealDouble() + b.getRealDouble());
    }
);