make lipstick work with PIG-4060

The changes include:

1) PIG-4060 changes TezJob to implement Runnable instead of extending ControlledJob. So there is no longer getState() that returns ControlledJob.State. Instead DAGStatus.State is used now.
2) #1 requires tez-api.jar as dependency.
3) Bumps joda-time to 2.1 to be on par with Lipstick master and Pig.
4) While testing MergeJoin test queries from Pig e2e test suite, I fixed NPEs in TezPlanCalculator-

java.lang.NullPointerException
	at com.netflix.lipstick.TezPlanCalculator.connectUnknownOperators(TezPlanCalculator.java:373)
java.lang.NullPointerException
	at com.netflix.lipstick.TezPlanCalculator.connectUnknownOperators(TezPlanCalculator.java:352)