Add a new comments plugin, that provides several types of comment to the flot chart.

Add a new comments plugin, that provides several types of comment to the flot chart: **tooltip**, **callout comment**, **side note**, ...

**Online Demo:**

http://jeff-tian.github.io/jquery.flot.comments.js/src/examples/CommentExample.html

**Screen shot:**

![screenshotforcommentplugin](https://f.cloud.github.com/assets/3367820/1720790/9ab8caa6-620d-11e3-9634-aadf408dd937.png)