Remove duplicated code

1) Remove pure-python `maps.py` in favor of Cython version  (addresses #23)
2) Rename cython `maps_fast` code to `maps`
3) Remove cython `base_fast.{pyx,pxd}` in favor of pure-python version
4) Small amount of whitespace cleanup'
5) Remove `maps.c`

Haven't yet removed `helloworld.c` due to Issue #38.

Addresses Issue #37.