Adding cconfig parent class for XML configuration

Adding cconfig parent class for XML configuration

Adding cconfig parent class for XML configuration

Added cconfig parent class for cvirtual_sensor_config and
csensor_config. Removed config namespace as XML configuration
related code is small to have a separate namespace. Cleanup of
namespace related code. Changed derived class
cvirtual_sensor_config and csensor_config classes code based
on new cconfig parent class

Change-Id: I296dc7be45b201c70d040e7dac2e2b5325d5abc5