Note we also consider the height of images; if an image is too high, 0.8\textheight will be used for beamer slides, and \textheight is used for articles (see http://tex.stackexchange.com/q/11954/9128).
If the user has explicitly provided the width/height options in \includegraphics[], our defaults will be overwritten, and this approach is better than the check `\@ifnextchar[` after \includegraphics because the latter approach simply gives up everything once it sees [, whereas \setkeys{Gin} can keep the good defaults unless they are explicitly overwritten in [].
closes#30, closes#28, and closes#26
In the old solution there was no way to use a LaTeX image where only the
height was used to scale the image -- the width was always implicitly
set as well leading to wrong aspect ratios.
Provide a command \Oldincludegraphics which does just what
\includegraphics would do in the LaTeX template. That we the same input
markup could be used for beamer and LaTeX templates.
This code (from the latex template) was causing bullets
and list numbers to extend beyond the left edge of the slide
in beamer.
Removing it seems to fix things.
