#263 Unnecessary warning about shadowed variable

[Gidi_Avrahami]

Doing

from numpy import *

Leads to this:

Warning: Module numpy.core.memmap is shadowed by a variable with the same name.

Apparently, numpy provides the class 'core.memmap' at the top namespace. So we have two issues here:

(1) The "shadowed" warning is incorrect -- this is the same variable

(2) I don't want to see warnings about numpy, since I have no access to its source (same complaint as in #1879931, so it may have already been addressed)