[SPARK-12265][MESOS] Spark calls System.exit inside driver instead of throwing exception

This takes over #10729 and makes sure that `spark-shell` fails with a proper error message. There is a slight behavioral change: before this change `spark-shell` would exit, while now the REPL is still there, but `sc` and `sqlContext` are not defined and the error is visible to the user.

Author: Nilanjan Raychaudhuri <nraychaudhuri@gmail.com>
Author: Iulian Dragos <jaguarul@gmail.com>

Closes #10921 from dragos/pr/10729.