Fix double insert error

When we have tls = ${tls}, we should *copy* the section,
instead of adding it as a reference.  When it's added as a
reference, it's inserted into the parents linked list of
children.  Having multiple references to the same section means
that the linked lists get completely screwed up.
Be more careful in name2_cmp
Clean up sub_find_name2

It turns out we don't insert ourselves into the name2 tree.
When we don't find (name1, name2) in the name2 tree, we have to
check if *we* are the thing being looked for