Log Message:
Update from version 0.90 to 0.91.

Upstream changes:

2009-01-16  Jarkko Hietaniemi  <jhi@iki.fi>
	* Minor documentation cleanups.
	* Add 'use strict;' to lib/Graph/TransitiveClosure.pm.
	* Modernize the META.yml.
	* Release as 0.91.