[NTG-context] \placefootnotes at the end of each chapter, conditionally

[Alan BRASLAU]

I have a simple problem:

I would like to place

\startsubject[title=Footnotes]
    \placefootnotes
\stopsubject

at the end of each chapter, thus effectively before each \stopchapter
BUT only if there are footnotes to be placed, i.e. I do not want to
have empty Footnotes subjects appearing in my document.

Supplementary question, just for fun:
how to specify title=Footnote if there is only one?

Thanks

Alan