If $counter == $def_count and the next tag in the list is a used tag, the
tagcloud_extra div would be printed twice, breaking the list.
This solution feels ugly, perhaps there's a better way to do this?
Wrong variable name, and don't do the math unless we have to.
Fixed the diplayed number being wrong.
Also fixed a corner case where number of tags in the cloud equals number to
display. Would display "[show 0 more tags]".
