Sara Popham

Made a hacky fix to this: https://github.com/gallantlab/pycortex/commit/8a452c3c7b4aff7f750d9e5440c43c03c276e4aa This issue may come up in other places where polyutils.voxelize is used though, I just haven't run into any yet

We need to put the `S1_retinotopy.hdf` somewhere from which it can be read by these scripts. Is it too big to put into the examples/quickstart/ folder?

Also we need to put the MNI brain in the default pycortex store if we want to be able to do that, I think