Removed downloadable and virtual product types in favour of a
downloadable/virtual checkbox option meaning variations can also now be
virtual (no shipping) or downloadable. This should make it more
flexible.
Not many changes were needed to template since simple, downloadable,
and virtual were all pretty similar anyway.
Added a filter for admin for the new sub-types.
In the future variations should have boxes too for downloadable/virtual
so you can mis it up with physical/downloadable goods in the same
product :)
Mike Jolley
Mark Jaquith