Restore original pom packaging settings to help Gradle builds

Using the maven dependencies from Gradle doesn't pull any artifacts or sub-dependencies. It seems this is because Gradle.Ivy isn't picking up the ${packaging} variable inherited from the parent pom when resolving. If I replace all the ${packaging} references with 'jar' and rebuild Infinispan then it works, at least for infinispan-core - org.infinispan:infinispan still doesn't grab anything, not sure if it should though.

Fixes appropriate for ivy/ant don't work for Gradle i.e. it doesn't pick up ivy config files.