* MLE and L1 loss functions
* logsoftmax change and tests
* subtract max logit for numerical stability
* l1 name change
* cross entropy reduction + unit tests
* docstrings
* l1 test name change
* old loss impl + default none
- The exponent and base were swapped because accelerate is using
exponent-base instead of base-exponent
- Fix also the test for binary ops as it was testing op(x, x) which
couldn't catch ordering errors like that
