QPID-4518 : disallow unknown args in config file
Change EnvOptMapper::configFileLine to take ar arg telling it if
it's OK to have unknown args or not.  If not, throw upon encountering.
From the higher level of run_broker(), there are two passes of
arg parsing.  In the first pass it's normal to have unknown args,
because the loadable modules are not loaded yet.  But I change the
second parsing to pass down the arg that says "unknowns are not okay."



git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1431016 13f79535-47bb-0310-9956-ffa450edef68