added stopwatch example

added requestAnimationFrame polyfill

moved raf logic into a subscription

separated logic into multiple files, all state lives in a global namespaced model, reset no longer sends multiple actions only one

examples/stopwatch/utilities/format.js

@@ -0,0 +1,15 @@
+function formatMinutes (minutes) {
+  return `${minutes >= 10 ? minutes : (minutes < 10) ? '0' + minutes : '00'}`
+}
+
+function formatSeconds (seconds) {
+  return `${seconds < 10 ? '0' + seconds : seconds}`
+}
+
+module.exports = function format (elapsed) {
+  const minutes = formatMinutes(Math.floor((elapsed / 1000) / 60))
+  const seconds = formatSeconds(Math.floor((elapsed / 1000) % 60))
+  const ms = formatSeconds(Math.floor((elapsed % 1000) / 10))
+
+  return `${minutes}:${seconds}.${ms}`
+}