[Pyrex] prototype for pow() causes trouble

[Leif Strand]

Quick bug report:

Pyrex inserts its own prototype for pow() instead of #including 
<math.h>. This is probably a bad idea. It caused problems for one of our 
builds. We compile the Pyrex-generated C code using a C++ compiler, and 
eventually the compiler sees the real prototype for 'pow':

PyLithLib.cc:13: error: declaration of 'double pow(double, double)' throws different exceptions
/home/buildbot/opt/ibinbot/include/apbuild/glibc-2.2.1/bits/mathcalls.h:143: error: than previous declaration 'double pow(double, double) throw ()'


--Leif