add basic reveal.js setup

taken from https://github.com/hakimel/reveal.js/releases/tag/2.6.1
convert outline to reveal.js form
got basic reveal.js + leaflet + stamen integration working

note that iframe used due to discussion on http://stackoverflow.com/questions/20119488/how-to-embed-a-leaflet-map-into-a-reveal-js-presentation
add singapore marker
add div overlays to illustrate 0 or 1 choices as red or green
expand size of 0 1 to fill area more fully
Merge branch 'leaflet'