POM: simplify repositories block further
Update license and file headers for 2014

This was done using:
  mvn license:update-project-license license:update-file-header
POM: remove redundant inceptionYear
POM: remove no-longer-needed configuration blocks

The removed sections have all migrated to the pom-scijava parent.
POM: tweak org name

We aren't actively using "ImageJDev.org" anymore. It was awkward.
POM: update issue tracker URL to GitHub Issues
POM: use more specific CI URL