Spelling error of aggregation
[TEST] use a dedicated port range per test JVM

For reliability and debug purposes each test JVM should use it's own
TCP port range if executed in parallel. This also moves away from the
default port range to prevent conflicts with running ES instance on the local
machine.
[TEST] only expand to 1 replica in SnapshotBackwardsCompatibilityTest
Test: Increase the ping timeout to avoid that a candidate master node makes the decision to elect itself too soon.
[Tests] add a debug logging message when starting an external node
[TEST] Fix RandomScoreFunctionTests#testConsistentHitsWithSameSeed
[CORE] Make network interface iteration order consistent

Today the iteration order of the interfaces might change across JVMs
this commit cleans up the NetworkUtils class and attempts to ensure
consistent iteration order across JVMs.