dtiInit mex file fixes and error in dtiFitTensor

[dorahermes]

I am running dtiInit on a Mac with Matlab R2019a and get several errors with the mex files when running dtiInit. I could easily resolve some my recompiling with the code suggested in dtiCompileMex, but this needs serious updating (see suggestions below) and dtiFitTensor is not running correctly. My current work around is to use the dtiInit docker (https://hub.docker.com/r/vistalab/dtiinit/), but the dtiFitTensor needs to be fixed. Am happy to troubleshoot or test.

----- necessary updates to dtiCompileMex -----
compatibleArrayDims needs to be added to the mex build code:
dtiFiberTracker.c builds & runs correctly with:
mex -O -compatibleArrayDims -I./jama dtiFiberTracker.cxx

dtiSplitTensor.c builds/runs correctly with:
mex -v -compatibleArrayDims dtiSplitTensor.c

----- error-----
dtiFitTensor.c
It needs to have zero removed after return from line 594 to compile, but output is not sensible (zeros instead of pdd).