HADOOP-9245. mvn clean without running mvn install before fails. Contributed by Karthik Kambatla.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1446019 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-9246. Execution phase for hadoop-maven-plugin should be process-resources. Contributed by Karthik Kambatla and Chris Nauroth

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1446020 13f79535-47bb-0310-9956-ffa450edef68