[IronPython] sympy on IP 2.6B2

[Dino Viehland]

Michael wrote:
> An undefined name is an undefined name. Sympy must be doing some magic
> somewhere to inject the name into the namespace.

If I had to guess that magic could be something involving imports.
There's another import bug Harry wants me to look at before 2.6 is done
so I'll try and see if this could be the same issue.  There's something
strange going on w/ circular imports and publishing back into sys.modules
during the import process.