Consistency with the SPARK-1126 proposal

Made available the following options:
    --executor-cores as replacement of --cores
    --executor-memory as replacement of --execmem
    --driver-memory as replacement of --drivermem

Marked as deprecated, but still supported:
    --cores
    --execmem
    --drivermem

Updated other new options to use '-' instead of '_'

[SPARK-1186] : Enrich the Spark-Shell Script to offer additional arguments.

Author      : bernardo.gomezpalacio@gmail.com