Create CDH and SPARK elements for savanna image builder
Modify spark element, fix error: not found javac
Modify Spark element: clean spark after building
Rename Create Image script
Add instruction of diskimage-create-cdh-spark.sh in README.rst
Correct README.rst
Modify repository README
Modify Spark element using binaries, skipping recompile
refactoring how spark is built
fixing spark sources from bin to src
fixing Hadoop versions
fixing Hadoop versions, typos
fixing Hadoop versions, cleanup. JAVAC is not installed
fixing spark, going for a distrib
fixing download location
fixing spark distrib dowload location: temporarily set to dropbox
adding a fix to CDH installation: log4j
fixing semicolon
fixing ownership
fixing bug in path