changes for new pipeline::Wrap<T>
introduced gap between images of an image stack
Merge branch 'master' of github.com:funkey/imageprocessing

Conflicts:
	gui/ImageStackView.cpp
got rid of warnings
added ComponentTreePruner to reduce the height of a component tree
improved ImageStackDirectoryWriter: creates directory on demand
made ImageStackDirectoryWriter save in tiffs with float
made ImagePainter more intelligent: if values exceed 1.0, it colors such that neighboring values have different hue
Merge branch 'master' of github.com:funkey/imageprocessing
small fix for hue value in ImagePainter
added hover annotations for image stacks
updated dependency vigra -> vigra-git
added ColorImageWriter
made ColorImageWriter more error robust
bugfix: ImageReader and ImageCrop create images that own their data, now
changed target type to OBJECT
removed obsolete destructor in MserParametersCollector
bugfix: made Image own its data

This was a problem if the creator of an image was destructed and a
reference to the image was still around. This can happen if a
pipeline::Value<Image> got sneakily casted into boost::shared_ptr<Image>
-- the pipeline gets destructed, the image is alive.
added initial value to constructor of Image
adjusted ImageStackHdf5Reader for new Image