LivenessAnalysis: Cache BB liveness info to improve performance
Brings down runtime of gcj_2014_1c_b.py from 2secs to 0.7
Add 'make analyze' to call the clang static analyzer

Also fix some of the things that it reported.

Have to patch the tool to make it work, since it wants
to use the CLANG_CXX environment variable to pass information around,
but the Pyston Makefile uses that variable as well.
Improve the performance of sum()

Move some things to calling the *Internal methods,
which don't do patchpoint-checking, which wouldn't apply.

Reduce some unnecessary string-creation.
Cut down on unnecessary string copies
Merge pull request #62 from undingen/cache_liveness

LivenessAnalysis: Cache BB liveness info to improve performance
Implement list.index()