Variable renaming

This wiki contains all the function parameter name changes/cleanup for POT 1.0

------------------documentation/examples------------------

n -> n_source_samples xs/xt -> x_source/x_target G0/Gs -> Gamma_emd/ Gamma_sinkhorn (May be ?) reg parameter entropic -> epsilon (blur ?) d (dimension parameter) -> n_features N (barycenter example) -> N_distributions X1 -> X_source (color transfer)

------------------variable names------------------

numItermax -> maxiter numInnerItermax -> maxiter_inner stopThr -> stop_threshold (reg -> blur ?) log (variable not bool) -> log_{namefunction}

numIterMax -> maxiter (scikit-learn compatible)