Redefine enc for better 3.x compatibility

Taking Benoit's advice from PR #6.
Remember to decode data from subprocesses
Ignore spurious EPIPE errors

Benoit says that newer Python's will generate ignorable EPIPE errors.
Trusting him and adding a pass through for it. This commit probably
breaks ghp-import for older versions of Python. If anyone complains I'll
think harder about how to fix this.
Disable universal newlines on Python 3.2.x

Acting on advice of Benoit.