Open MEEG error #139 when running the headmodel computation

[Francois]

If the error message is not the same, please post the new error message you get.
You can copy-paste the full error message from the Matlab command window.

If you are working on a Mac, please refer to this thread:

OpenMEEG error #134: dyld: library not loaded

I pushed this commit, which will keep the /bin and /lib subfolders only on MacOS: Users facing this bug should just have to update Brainstorm and re-run the computation of a OpenMEEG forward model, it should update everything automatically on the OpenMEEG side. I haven't tested this fix, I'm working blindly because I don't have access to a mac at the moment. I'd need someone with a MacOS system to try it.