- Suppressed IOErrors which can raise when program output pipe
is closed under a program like ``head``; however this only
works on Python 2.  On Python 3, there is not yet a known way to
suppress the BrokenPipeError warnings without prematurely terminating
the program via signals. fixes #160.
Added comments to http://bugs.python.org/issue11380 to see what the
status is on py3k.