title: R Markdown (Pandoc) beamer presentation with short title
body: <p>I am trying to use <code>beamer_presentation</code> in RMarkdown and in the YAML header I include, say, <code>title: "Long title"</code>. This title appears on the first title page of my slides but also at the bottom of all slides. However, at the bottom of all slides I would like a shorter title to appear. I wonder if something like <code>short-title: "Short title"</code> could be used. I know that there is <code>uiucthemes</code> that allows that, but I don't want to use the uiuc style.
  Thanks!</p>