[Pyrex] Python 2.5 exceptions

[Phillip J. Eby]

FYI, the "raise" statement doesn't appear to work correctly under Python 
2.5, since exceptions are new-style in 2.5, but Pyrex allows only classic 
exceptions.

(It would be nice if, when this is corrected, it is done in a way that 
still allows the same generated C code to be used for Python 2.3 and 2.4 as 
well, since that allows me to have a single source distribution and not 
require the person doing the installing to have Pyrex.  On the other hand, 
now that Pyrex is easy_install-able, I could just make my packages define 
it as a setup_requires requirement and automatically install Pyrex during 
building if needed, so if that's what has to happen, I can deal.)