ver 0.1
version 0.2, use flot.js
version 0.21, do a clean up on v0.2
version 0.22
1. use django.forms instead of HTML form
2. use spinner instead of textbox for process
3. add superuser validation
version 0.23
1. story lists
2. IE 8 support
3. commit time interval restriction
4. chart time window in burndown.js
ver0.24
1. plot add annotations and enable navigation:pan
2. show errors infomation