New getAllValsBetween causes Python test failures

[naoyam]

With the new getAllValsBetween implementation introduced in PR #729, the following three Python tests fail:

ERROR: test_dropout_training_fusion (__main__.TestCudaFuser)
ERROR: test_layer_norm_autodiff (__main__.TestCudaFuser)
ERROR: test_native_layer_norm (__main__.TestCudaFuser)

#773 reverts the change and moves the old version back. The new version is still there as getAllValsBetween2. We should incrementally change the use of getAllValsBetween to getAllValsBetween2 to find out which use of the function causes the test failures with the Python tests.