Issue #2 fix, plus Beth Ashinsky's Linear Regression code

Sorry about the massive PR. It combines Simon Li's test code that exposed Issue #2, the fix to Issue #2, as well as the extra code in FeatureSet.Py to do linear regression required by Beth Ashinsky. The two dev branches I had to work on Simon's stuff and Beth's stuff got intermingled and I was too lazy to unmingle them. This PR also seems to include the code in setup.py that is smart about running ./configure, i.e., only runs it if config.h hasn't been created.