This test was failing because the hash computes values greater than
0x7fffffff, which 32-bit python2 promotes to long, which `hex` formats
with a trailing 'L'. The code that uses it appears to be ok with a
long value, so it's just the test that needs to handle it.
Fix as suggested here:
https://stackoverflow.com/questions/5917203/python-trailing-l-problem
This still picks up the 2.7 type annotations in comments.
Fix the compute_quadratic signature to allow for the ValuewView of an
OrderedDict in python 3.
The 'lib/cretonne' directory will be the new root of a stand-alone
cretonne crate containg both Python and Rust sources.
This is in preparation for publishing crates on crates.io.
