Imglib2 image server

[Rylern]

Add an ImageServer that get pixel values from one or more RandomAccessible.

See the README for more information on how to use it.

[petebankhead]

This looks great and the performance is pretty good considering the potential overhead.

I tried it with the following script:

import qupath.ext.imglib2.imageserver.*
import qupath.ext.imglib2.ImgCreator
import net.imglib2.view.Views

var server = getCurrentServer()

var imgCreator = ImgCreator.builder(server).build()

var imgs = []
for (int i = 0; i < server.nResolutions(); i++) {
    imgs << imgCreator.createForLevel(i)
    // Alternative (slower, but shows a difference)
//    imgs << Views.rotate(imgCreator.createForLevel(i), 0, 1)
}


var server2 = new ImgLib2ImageServer([], server.getMetadata())

var path = buildPathInProject("example.ome.tif")
writeImage(server2, path)

I requested some smallish changes - the performance-related ones may not be worth it, since my timing experiments were inconclusive.

[Rylern]

The comments were addressed.