Results 2 issues of marcwang

It seems the tail_res go through log_softmax twice: [line 65](https://github.com/salesforce/awd-lstm-lm/blob/master/splitcross.py#L65) and [line 163](https://github.com/salesforce/awd-lstm-lm/blob/master/splitcross.py#L163). What is the meaning behind it? Thanks a lot.

After running ```python python setup.py build_ext --inplace ``` When I try importing _sparsemap, an error occurs: In [1]: import _sparsemap \--------------------------------------------------------------------------- ImportError Traceback (most recent call last) in () ---->...