[O] Two ox-texinfo regressions

[Jonas Bernoulli]

Hello,

1) Starting with "1b415735e ox-texinfo: Small menu refactoring"
   a menu contains not only entries for subnodes but recursively
   for all subsub...nodes.

   That's because `org-element-map' is no longer called with `headline'
   as NO-RECURSION.

   You can use this trivial source to veryify this:

   .---
   |* a
   |** b
   |*** c
   `---

   This can be fixed by reverting that commit.

2) There no longer is an empty line between headings and content in
   texi files.  I am not sure what commit introduced that regression.

   You can use this trivial source to veryify this:

   .---
   |* title
   |
   |content
   `---

   This can be fixed by changing the last line of
   `org-texinfo-headline':

   .---
   |-             contents)))))))
   |+             "\n" contents)))))))
   `---


Best regards,
Jonas