Fixes an AWFUL oversight in .ignore!

For some reason, I though it would be a good idea to put *.py in
.gitignore; lesson learned.
Noise naming modifications.

Because the general "noise" namepsace is pretty vague, this patch
renames the existing code to better reflect that it is a libnoise
wrapper; this will allow us to add other things to the noise module in
the future, and improves Cython compatibility.