Revised net.imglib2.ui package.

This incorporates many changes and improvements I made in the BigDataViewer.

* Multi-threaded, multi-resolution rendering making GUI very responsive.
* abstracted from transform type Affine2D/Affine3D,
  avoiding code duplication.
* removed support for IJ1 ImagePlus as interactive display.
  Only JComponent is supported.
* The old InteractiveViewer2D, etc, have been updated to use the new
  rendering infrastructure with minimal interface change.
  Code relying on those classes should be easy to fix.

For simply using imglib-ui to display images see InterActiveRealViewer and
derived classes. InterActiveRealViewer is a default assembly of smaller
imglib-ui components that are hopefully reusable for less straightforward
scenarios.
updated (most of) the interactive examples for revised imglib2-ui.
brought back clamping n-linear interpolation for ARGBType in viewers
ImgPlus: undeprecate getImg method

Christian Dietz rightly points out that there are legitimate use cases
for obtaining the backing Img object. However, it is good to remind
people that in the usual cases, you do not need getImg() but rather can
use the ImgPlus directly.
Bump to next development cycle

Signed-off-by: Barry DeZonia <bdezonia@wisc.edu>
Fix constructor inconsistency

With commented code it was possible to throw an UnsupportedOperationException
when add()'ing an axis to the AxisList constructed using the inconsistent
constructor.
Remove old invalid calibration double[] array

The calibrations are stored with the axes directly. This removed code was a
holdover from an earlier time. This should fix possible inconsistencies.
setAxis() expands axisList if beyond end
Default axis calibration to NaN & no unit
Also copying Calibration now
QuantilFilter: added restriction on dimensions
Merge branch 'master' of https://github.com/imagej/imglib
Define calibrated real intervals
Remove the TEMP Named methods
Further progress with calibrated intervals
Add license blurbs and author tags
Eliminate remaining TEMP interface methods
Further decoupling of rendering classes:
 - abstract Renderer is extended by SimpleRenderer and
   MultiResolutionRenderer
 - made InteractiveDisplayCanvas an interface (implemented by
   InteractiveDisplayCanvasComponent)
 - split RenderTarget from InteractiveDisplayCanvas, so Renderer doesn't
   have to know about InteractiveDisplayCanvas
 - BufferedImageOverlayRenderer is a RenderTarget and OverlayRenderer,
   everything is painted through OverlayRenderers
UML class diagram for most of imglib2-ui.
added lots of javadoc. Use generic parameter name "A" for transform type consistently.