Move org.apache.oozie.action.hadoop.ActionStats to Oozie ShareLib

OOZIE-2852 moved ActionStats to oozie-core. Because of this Pig jobs are failing with java.lang.NoClassDefFoundError: org/apache/oozie/action/hadoop/ActionStats

Reproduction:

• I executed the pig wf example on a cluster with bin/oozie job -oozie http://localhost:11000/oozie -config examples/apps/pig/job.properties -run -DnameNode=hdfs://localhost:9000 -DjobTracker=localhost:8032. RM web UI show the OoziLauncher failed:

  State:	FINISHED
  FinalStatus:	FAILED
  Started:	10-Oct-2017 13:54:33
  Elapsed:	14sec
  Tracking URL:	History
  Diagnostics:	org/apache/oozie/action/hadoop/ActionStats
  

• Looking at the logs it turns out ActionStats is not contained anymore in the Oozie sharelib:

  java.lang.NoClassDefFoundError: org/apache/oozie/action/hadoop/ActionStats
          at java.lang.Class.forName0(Native Method)
          at java.lang.Class.forName(Class.java:348)
          at org.apache.hadoop.conf.Configuration.getClassByNameOrNull(Configuration.java:2013)
          at org.apache.hadoop.conf.Configuration.getClassByName(Configuration.java:1978)
          at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:2072)
          at org.apache.oozie.action.hadoop.LauncherAM.runActionMain(LauncherAM.java:404)
          at org.apache.oozie.action.hadoop.LauncherAM.access$300(LauncherAM.java:56)
          at org.apache.oozie.action.hadoop.LauncherAM$2.run(LauncherAM.java:223)
          at java.security.AccessController.doPrivileged(Native Method)
          at javax.security.auth.Subject.doAs(Subject.java:422)
          at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1628)
          at org.apache.oozie.action.hadoop.LauncherAM.run(LauncherAM.java:217)
          at org.apache.oozie.action.hadoop.LauncherAM$1.run(LauncherAM.java:153)
          at java.security.AccessController.doPrivileged(Native Method)
          at javax.security.auth.Subject.doAs(Subject.java:422)
          at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1628)
          at org.apache.oozie.action.hadoop.LauncherAM.main(LauncherAM.java:140)
  Caused by: java.lang.ClassNotFoundException: org.apache.oozie.action.hadoop.ActionStats
          at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
          at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
          at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
          at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
          ... 17 more
  

We should move ActionStats to sharelib (that is oozie-core's compile dependency).

( It might also make sense to create a docker based job to run the example workflows regularly to protect against this kind of failures in the future. Docker image could contain a simple, 1-node pseudo hadoop cluster and Oozie. )