Merge pull request #5 from chfw/master

close zipoutputfp at line 409. without the fix, cannot write the documen...
ODF2XHTML has no method make_embedable()

Initialize ODF2XHTML instance with embedable=True then will raise an
AttributeError, because there was no method named 'make_embedable', in fact we
want to invoke set_embedable().
Merge pull request #9 from BrickXu/master

Fixed the AttributeError when initialize ODF2XHTML instance with embedable=True