Minor bug in footnotes

Hi Carsten,

After some additional testing of footnote options, I discovered
another minor quirk. It occurs when org-footnote-section is set to a
value such as "Footnotes" (the default value). When
org-footnote-action is called for the very first time in an org
buffer, the "Footnotes" headline is automatically created, but the
footnote is placed above the headline.

I believe this occurs when the "Footnotes" headline is the last line
in the buffer, which is the case when the headline is automatically
created. Once an empty line is placed beneath the "Footnotes"
headline, new footnotes are correctly placed beneath it.

The example below illustrates the behavior.

Thanks,

Matt

----begin org file--------

* Headline one

The first footnote.[fn:1] The second footnote.[fn:2] Now I will add a
an empty line beneath the "Footnotes" section.[fn:3]

[fn:1] Notice that this footnote is inserted above the "Footnotes"
section.