Import speedup - Ticket #2181

Applies the patch submitted at http://projects.scipy.org/numpy/ticket/2181

see mailing list discussion:

http://mail.scipy.org/pipermail/numpy-discussion/2012-July/063130.html

especially - http://mail.scipy.org/pipermail/numpy-discussion/2012-July/063194.html - should polytemplate.py be run at build time instead of requiring it to be run manually when edited.