Changes

* Test of AIC model selection between diffusion tensors added to the test suite. (To catch [https://gna.org/bugs/? 5746 bug #5746])* Changing of the local tm parameter name of 'tm' to 'local_tm' to distinguish it from the global tumbling time 'tm'. (Preparation for fixing [https://gna.org/bugs/? 6384 bug #6384])

* Fix of bug where self.relax.data.select_sim was treated as a list. ([https://gna.org/bugs/? 5977 bug #5977])* The value.copy() function now handles the value of None. ([https://gna.org/bugs/? 6288 bug #6288])* The global flag is now set by the relax_data.delete() function. ([https://gna.org/bugs/? 6383 bug #6383])* The model-free model_statistics() function now tests for the presence of relaxation data. ([https://gna.org/bugs/? 5806 bug #5806])* Sorting of global from local parameters in 'generic_fns/value.py' simplified and fixed by changing the parameter name 'tm' to 'local_tm'. ([https://gna.org/bugs/? 6384 bug #6384])* Model-free parameters now set in the OpenDX mapping test of the test-suite. ([https://gna.org/bugs/? 6388 bug #6388])* Failure of model elimination because of a 'local_tm' and 'tm' mix up. ([https://gna.org/bugs/? 6389 bug #6389])* Modification of the model-free calculate() function and elimination of the 'combined' flag from the self.model_statistics() function. ([https://gna.org/bugs/? 5746 bug #5746])