Adjust Zest version numbers to other GEF4 bundles
[386029] Supplement image processing facilities.

- Discard ImageUtils.
  -> The functionality is now accessible through the Image and Color classes.
- Improve Color.
  -> Provide static utility methods to work with ARGB pixel-values. Those are
     extensively used by the image processing facilities.
  -> Delete IHSV. For now, only ARGB color abstractions are delivered.
- Improve Image.
  -> Load/Save image-files.
  -> Provide getScaled(...) and getThumbnail(...) methods to scale an Image.
  -> Add get*Histogram() methods to provide a simple analyzation basis.
- Javadoc enhancements.
  -> Almost all of the public API is reasonably documented.
- Facilitate CompositeChannelFilterOperations.
  -> Multiple AbstractChannelFilterOperations can be combined to a
     CompositeChannelFilterOperation. The appliance of the latter can be
     considerably faster than performing the individual operations sequentially.
[386029] Update examples.
Move Zest features to GEF4 p2 repository
Replace separate Zest parent pom with merged GEF4 parent
Merge branch 'master' of ssh://git.eclipse.org/gitroot/gef/org.eclipse.gef4
Make org.eclipse.platform.doc.isv dependencies non-optional
[386029] Use GEF4 Image instead of BufferedImage.
[NONE] Fix Ellipse.getIntersections(Line) for vertical Lines.
[NONE] Fix AbstractRectangleBasedGeometry#getShrinked(double, double, double, double).

Change the order of the parameters of the
AbstractRectangleBasedGeometry#getShrinked(double, double, double, double)
method to coincide with the #shrink(...) method.
[NONE] Fix AbstractRectangleBasedGeometry#getShrinked(double, double, double, double).
[238529] Add option to disable animation of graph layout changes
[386029] Add Color#getBlended(Color).
[386029] Add Image#toBufferedImage().

This method will most likely get removed in the near future. Although it would
be awesome if we could share image data rather than copying it.
[386029] Enhance javadoc comments.
[386029] Add ArithmeticOperations#getBlendOperation().
[386029] Add IFillMode and implementations.

Various fill operations (color-fill, gradient-fill, image-fill) are now provided
using the corresponding IFillMode implementation (ColorFill, GradientFill,
ImageFill).
[386029] Add IGraphics#draw(Point) to draw a single point.
[386029] Support IFillMode via IFillProperties.
[386029] Update tests for IFillProperties and IGraphics.