GSoC: week 7

Ack! This has been a really bad week for me! I'd like to blame it on the intermittent internet access, but the reality is that I've just come home after about 6 months and it's hard to avoid catching up "just a bit". I did manage to fix some of the unicode issues bringing us down to just two test failures and 9 exceptions, but I should've had it all working by now. In other news, Renato has worked some more on running in PyPy, bringing it down to one exception and 9 failures - it's quite possible that some of those are actually SymPy errors where we rely on some CPython-specific detail, those are going to be particularly interesting to track down.