Subtle time remaining bar

Adds the config option 'timeRemaining', which is a number of minutes as an integer. 

If set, it displays another small bar above the progress bar that slowly fills up as the timer counts down. Useful for when you need to keep track of how much time you have left when giving a presentation.

![timeremaining](https://f.cloud.github.com/assets/2036909/1183259/4f8dea3c-222c-11e3-912b-ab28208e09f9.png)