Added DEPRECATED versions of statistic and variance in streaming MMD

DEPRECATED versions are available with

 - statistic type S_UNBIASED_DEPRECATED
 - null variance estimation method NO_PERMUTATION_DEPRECATED
 - null approximation method MMD1_GAUSSIAN_DEPRECATED
Definitely, there should be a check on p_and_q!= NULL and then you can print the get_name() of the given (wrong) instance