support for CoSMoMVPA

CoSMoMVPA is a toolbox in matlab inspired by PyMVPA.

This PR provides
- dataset input/output support
- neighborhood (a.k.a. query engine) input support
- unit tests
1) you are correct -- my bad!
2) data here would be useful for a) doctesting -- i.e. to verify that documentation you have here is correct; b) unittesting -- it will be useful to verify that you do obtain those values you expected (might be part of the doctest, but we do unittests more often)
yes -- ```mvpa2/data/cosmo``` or ```mvpa2/data/cosmomvpa``` (you had a typo) should work imho ;)