add compiled SSE distance code. 20x speed of numpy
comment
some reorganization of setup.py
minimum image convention
We can do this without SSE4
Added all of the wrappers and tests
docstrings
cleanup whitespace
Add some dtype checks
CFFI based distance wrapper
use the typechecked version of the arrays, dummy
add cffi to travis setup
merge in master
Merge pull request #135 from rmcgibbo/distancecffi

Minimum image convention -- cffi