[PAXEXAM-283] use org.ops4j.master 2.0.0  [PAXEXAM-284] upgrade Pax Runner to 1.7.5
[PAXEXAM-283] use org.ops4j.master 2.0.0 
[PAXEXAM-284] upgrade Pax Runner to 1.7.5

Also cleaned up some plugin versions now inherited from the new master
POM.
koma-akdb/org.ops4j.pax.exam2,ops4j/org.ops4j.pax.exam2,koma-akdb/org.ops4j.pax.exam2,The-Alchemist/org.ops4j.pax.exam2,bimargulies/org.ops4j.pax.exam2,bimargulies/org.ops4j.pax.exam2,ops4j/org.ops4j.pax.exam2,The-Alchemist/org.ops4j.pax.exam2