Add Sparkling Water launcher.
Shell script to launch bare Sparkling Water on top of Spark.
Refactoring of cloud building.

Added more elasticity:
 - if number of h2o workers is not specified then it is guessed based
 - now we can build h2o cloud only on the subset of Spark workers
  - nevertheless, it is dangerous, since we will lost expected good
mapping between partitions and chunks
Shell script refactoring

Changes:
  - common code moved to shared sparkling-env definition
  - removed code containing explicit number of workers
Explicit number of nodes removed.
Documentation updated.
Removed obsolete demo.
Pass parameters to example runner.
Distribute test files via Spark API.