POM: bump to pom-scijava 1.161

This updates the version of ImgLib2 to 2.0.0-beta-26, and adjusts
accordingly for breaking API changes.

It also updates scijava-common to 2.15.0, which includes many new
services migrated from ImageJ core.
Migrate to SJC version of core services & plugins

See:
https://github.com/scijava/scijava-common/commit/3aa51f812fef19cd14e3adea4d4aa5e3b395f1ea
POM: add dependency comments
Organize imports
WIP: Migrate to ImageJ Common component

See:
https://github.com/imagej/imagej-common