See my commit message:
Downgrade to maven-jar-plugin 2.3.2 due to a bug in m2e:
https://bugs.eclipse.org/bugs/show_bug.cgi?id=406507

maven-jar-plugin 2.4 doesn't bring anything to wiQuery and it makes the contribution more painful.

It's not a mandatory change but it makes working with Eclipse, M2E and wiQuery painless.