Multidimensional channels processing

[rmaree]

Add a contrast stretch (http://homepages.inf.ed.ac.uk/rbf/HIPR2/stretch.htm) per channel function in the Explore view. Either:

• Use imagelayers and imagej/fiji code (like other imagelayers)
• use a javascript library with controls and html5 canvas e.g. http://camanjs.com/ http://camanjs.com/examples/