[src] Removed MultivariateGaussianCharacteristicFunction file. Module uses ot version >= 1.2
[src] Removed useless code : we rely only on multiprocessing.Pool for parallelization
[src] Removed sequential computePDFOn3DGrid. Now we only use the parallel version
[test] updated test_4_3_perf_test.py due to changes in the library
[test] added trace of test_4_3_perf