v2.0.0-pre1
  feature: progress bar no longer shows before focusing on progression element, closes #10
  feature: each progression popup (formerly 'tooltip') now has a unique id
    and can be styled with css, closes #15
  feature: the ``data-helper` attribute is eliminated, the 'help' text goes
    in `data-progression`, closes #6 and aarondo/progression.js#6
  js: source is now in CoffeeScript
  css: .percentagebar is now .progressbar, closes #7
  js: options: showHelper is now showFraction, but disabled, closes #9
  js/css: now using css class .progression instead of {.tooltip,.syco_tooltip}, closes #11
  css: all classes have been renamed, relying on CSS1 nesting, closes #11
  css: options.animate and css .animate now use the same nomenclature, closes #16
  js: progress bar is now animated by default, optimization! closes #13
  js: options: all options have been renmaed shorter, closes #14