Comment 1 for bug 397654

Merged to storm/trunk r313:

Michael Hudson 2009-07-22 [merge]
Merged unary-minus [r=jamesh,niemeyer] [f=397654]

A new Neg expression provides support for unary minus. A minus is
automatically prepended to the expression passed to Neg. A couple
of failures in the Zope doctest related to differences in repr
formatting between python2.5 and python2.6 have also been fixed.