[Bioperl-l] tests

[Heikki Lehvaslaiho]

I went to a really boring meeting and there was no network connection,
so I ended up fixing bioperl tests to better skip individual tests when
network is down. 

The only remaining test files with failures (under linux and perl 5.8.1)
are BioGraphics.t and Registry.t. Brian is working on the latter and
Lincoln has previously hinted that there might be a better way of
testing png file generation. Would be nice to see it in place.

	-Heikki