timer-promise

This is an adaptation of Wongoo Lee's timer-promise library. Thanks, Wongoo!

Stuff I added ontop of the original:

* UMD modules for frontend use.
* Typescript definitions.
* Use ES6 Promises (or a polyfil) instead of bringing it in via node require().

Promise version of setTimeout and clearTimeout

You can start and stop timer like this.

``js
var timer = require('timer-promise');

Timer.start('foo', 5000).
then(function() {
}, function(cancelled) {
});
...
Timer.stop('foo');
`
instead of
`js
var timeoutId = setTimeout(function() {
}, 5000);
...
clearTimeout(timeoutId);
``