Bump to pom-scijava 2.0
Remove hardcoded ImageJ repository
Add managed ImageJ component versions

These lived in pom-scijava prior to its 2.0 release. Now they live here
in pom-imagej; this is a more modular and extensible design.
Add imagej-maven-plugin configuration

This lived in pom-scijava prior to 2.0.
Add ImageJ developer profile for SNAPSHOT pinning

This feature lived in pom-scijava prior to 2.0.