doc/sphinx/arm/config-backend.rst

doc/sphinx/arm/config-backend.rst

[914-move-to-c-11-thread-library-in-core-library-code] Upgraded thread/mutex code in the core library to C++11

[168-config-manager-clear-does-not-clear-the-d2-client-config-full-clear] Fixed unit tests using previous CfgMgr clear() behavior

[168-config-manager-clear-does-not-clear-the-d2-client-config-full-clear] Changed CfgMgr clear() to reset D2ClientConfig

    src/bin/dhcp4/tests/dhcp4_srv_unittest.cc
        Cleaned up failure text

    src/lib/testutils/gtest_utils.h
        Replaced array with vector

src/bin/dhcp4/dhcp4_srv.cc
    Dhcpv4Srv::processRequest()
    Dhcpv4Srv::processRelease()
    Dhcpv4Srv::processDecline()
    Dhcpv4Srv::processInform() - now all call sanityCheck()

src/bin/dhcp4/tests/dhcp4_srv_unittest.cc
    TEST_F(Dhcpv4SrvTest, sanityCheckDiscover)
    TEST_F(Dhcpv4SrvTest, sanityCheckRequest)
    TEST_F(Dhcpv4SrvTest, sanityCheckDecline)
    TEST_F(Dhcpv4SrvTest, sanityCheckRelease)
    TEST_F(Dhcpv4SrvTest, sanityCheckInform) - new tests

src/lib/testutils/gtest_utils.h
    New file with handy new test macros:
        EXPECT_THROW_MSG()
        ASSERT_THROW_MSG()

src/lib/testutils/Makefile.am
    Added new file gtest_utils.h

Added a ChangeLog entry

This checks that selected packet statistics is set to 0 before the test.