- amending d81619b50b9df7ff4458:

Revision files are now written out using the ``'wb'`` modifier to
``open()``, since Mako reads the templates with ``'rb'``, thus preventing
CRs from being doubled up as has been observed on windows.  The encoding
of the output now defaults to 'utf-8', which can be configured using
a newly added config file parameter ``output_encoding``.
fixes #234