Use institute iff \myinstitute defined
Put \theversion in footers iff it's defined
Loading iftex.sty for Beamer, URL styling in handouts, centred frametitles, no title for handout bibliographies
Structure slides before sections now have no slide number, and don't increment the counter; columns are ragged at the bottom; more spacing between \item s
Merge branch 'master' into For-GitHub
Structure slides before sections now have no slide number, and don't increment the counter; columns are ragged at the bottom; more spacing between \item s
Now using iftex.sty
Put \theversion in footers iff it's defined
Use institute iff \myinstitute defined
Loading iftex.sty for Beamer, URL styling in handouts, centred frametitles, no title for handout bibliographies

Signed-off-by: Thomas Hodgson <thomas.hodgson@gmail.com>