add destructor and deallocate the mIstDb; c++ formatting style improvements and formatted with astyle -s3 -p -H -A3 -k3 -O -o -y -Y -f
replace the LOG_INFO with LOG_DEBUG to slim the log file
c++ format style improvements; virtual keyword added for destructor
Made class getters const because we change nothing in the object
Set class version to 1 as version 0 has a special meaning in root cint world
StIstDb: Removed unused header includes
StIstDb: Reduced the scope of the using namespace