ArgumentDefaultsHelpMultilineFormatter class
ArgumentDefaultsHelpMultilineFormatter class

This allows the argparse user to split lines in the help text prolog
by including a "%%n" sequence.

Change-Id: If76b6217b71405c098619e76b97610de043d2a32
Signed-off-by: Michael Walsh <10404802c7de463f402c4a18638106ca1b12ef61@us.ibm.com>

openbmc/openbmc-test-automation,openbmc/openbmc-test-automation