Redundant edges argument in pseudo_gravity_packing

[heinsimon]

The documentation and the function header include the argument 'edges'. Changing this argument from default value does not change anything in the output.

Checking the source code revealed: it is not used within the function itself.

I would expect either an error/warning when changing the argument from default value or not having this argument at all.

[jgostick]

That function is in need of some fixes. I think there are already some bug reports on the issue tracker so I'll affect this to the list.