Organize imports
POM: bump to pom-fiji 5.0.2

This updates to the latest SciJava software components.

It also uses release versions for all Fiji components,
except for legacy-imglib1, which has no release version,
and Stitching_, which needs another release itself first.
Merge branch 'master' into remove-imglib1-deps

Clean the pom to make use of ImgLib2 methods and remove dependencies from ImgLib1 and Stitching.
In FeatureStack.java, reorganize imports accordingly.

Conflicts:
	pom.xml
	src/main/java/trainableSegmentation/FeatureStack.java