Include option_parser and impala_shell_config_defaults in the Impala shell tarball.

This makes the shell package work; Previously, it threw import exception and exited.

Change-Id: Iec6a7a751311c66966fa5636c4d3a522ff15ab87
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/3699
Reviewed-by: Lenni Kuff <lskuff@cloudera.com>
Reviewed-by: Ishaan Joshi <ishaan@cloudera.com>
Tested-by: Ishaan Joshi <ishaan@cloudera.com>