Rename version.org.picketbox to version.org.picketbox.picketbox-infinisp...

...an, because it's not the version of picketbox itself.
After this, version variable name fits repository location and is inline with version variable for picketbox-commons.
.m2/repository/org/picketbox/picketbox-infinispan/4.9.0.Beta1/picketbox-infinispan-4.9.0.Beta1.jar
.m2/repository/org/picketbox/picketbox-commons/1.0.0.final/picketbox-commons-1.0.0.final.jar