new paused mode feature (closes #144), controls and progress DOM elements are no longer required in HTML

Previously, descenders from characters like 'g' or 'y' were truncated (overflow: hidden)

rm extrenous whitespace

themes are now available as separate css files under css/theme/, old theme option in config is no longer supported (closes #104)

this way, more browsers are supported, like older Opera/Chrome/FF

this way things are in Impact; Impact fits much more with the visual style than does the default Arial or Calibri.

use mq to reduce font size for low resultions, max limit on width for slides set to 900px (closes #49)