fixed typo in sxform (was sxfrom earlier), vectorized a few functions, wrote tests for a number of gf* functions, decided to keep the spicecell results format for these to keep consistant with icy. Small updates to README.
Merge pull request #37 from Apollo117/gf_tests_first_pass

fixed typo in sxform (was sxfrom earlier), vectorized a few functions, wrote tests for a number of gf* functions, decided to keep the spicecell results format for these to keep consistent with icy. Small updates to README.