Updated spark-shell in .deb
Added compute-classpath.sh to .deb
Added HADOOP_CONF_DIR to debian-packaged compute-classpath.sh
Merge SPARK_JAVA_OPTS
  - eliminate duplicate SPARK_JAVA_OPTS
  - allow Worker Local options of the form key=value or k:value
    to override Application level options that have the same key
  - log an error if options with the same key are specified within
    the Application or Worker Local level.