[SPARK-1516]Throw exception in yarn client instead of run system.exit

    [SPARK-1516]Throw exception in yarn client instead of run system.exit directly.

    All the changes is in  the package of "org.apache.spark.deploy.yarn":
        1) Throw IllegalArgumentException in ClinetArguments  instead of exit directly.
        2) In Client's main method, if exception is caught, it will exit with code 1, otherwise exit with code 0.
        3) In YarnClientSchedulerBackend's start method, if IllegalArgumentException is caught, it will exit with code 1, otherwise throw that exception.
        4) Fix some message typo in the Client.scala
    After the fix, if user integrate the spark yarn client into their applications,
    when the argument is wrong or the running is finished, the application won't be terminated.

+CC dbtsai mengxr

Author: John Zhao <codeboyyong@gmail.com>

Closes #1099 from codeboyyong/branch-0.9 and squashes the following commits:

00144b5 [John Zhao] use e.printStackTrace() to replace "Console.err.println(e.getMessage)" so that client console can  get more useful information when somthing is wrong.
addcecb [John Zhao]   [SPARK-1516]Throw exception in yarn client instead of run system.exit directly.