Reduce MAGPIE_SHUTDOWN_TIME default to 15 minutes
Fix regex to match Hadoop 2.2.X appropriately
Move YARN_CONF_DIR & YARN_LOG_DIR to magpie-common-exports, also set HADOOP_YARN_HOME, HADOOP_HDFS_HOME, HADOOP_COMMON_HOME
set username for HADOOP_YARN_USER
Add various environment variables to hadoop-env.sh and yarn-env.sh