NO-JIRA: Fix defects found by coverity.

To view the defects in Coverity Scan visit, http://scan.coverity.com/projects/6?tab=overview

** CID 1224524:  Big parameter passed by value  (PASS_BY_VALUE)
/qpidbuilds/trunk/qpid/cpp/src/tests/BrokerFixture.h: 155 in qpid::tests::SessionFixtureT<qpid::tests::LocalConnection, qpid::client::Session_0_10>::SessionFixtureT(qpid::broker::BrokerOptions)()

** CID 1224525:  Big parameter passed by value  (PASS_BY_VALUE)
/qpidbuilds/trunk/qpid/cpp/src/tests/ClientSessionTest.cpp: 108 in qpid::tests::ClientSessionFixture::ClientSessionFixture(qpid::broker::BrokerOptions)()

** CID 1224526:  Big parameter passed by value  (PASS_BY_VALUE)
/qpidbuilds/trunk/qpid/cpp/src/tests/MessagingFixture.h: 106 in qpid::tests::MessagingFixture::MessagingFixture(qpid::broker::BrokerOptions, bool)()

** CID 1224527:  Wrapper object use after free  (WRAPPER_ESCAPE)
/qpidbuilds/trunk/qpid/cpp/src/qpid/broker/SaslAuthenticator.cpp: 276 in qpid::broker::CyrusAuthenticator::init()()

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1608487 13f79535-47bb-0310-9956-ffa450edef68