Add single mode for embedding initial slide
Add touchstart and touchend events
Better top positioning
Merge branch 'single'
Merge branch 'master' into 'touch'
Refine touch events
Preliminary touch handling for mobile devices

Merge branch 'touch'. This is a bit of a mess so far; in any case we
still have scaling problems. Will need help from the wild to sort this
out.
Further help to sizing