Added configuration parameters to the C++ SDK's generated documentation.

Added configuration parameters to the C++ SDK's generated documentation.

As pointed out by Bill Dieter in changeset 878, these defines are
inherently included by the the octypes.h file. To give end users the
definition of these defines, we must also include the configuration
parameters in the C++ SDK's documentation.

Change-Id: Iac98843920afae295dd86ac11236332c605b184e
Signed-off-by: Joseph Morrow <joseph.l.morrow@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/895
Reviewed-by: William Dieter <william.r.dieter@intel.com>
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Erich Keane <erich.keane@intel.com>