Merge pull request #11 from longchao/master

My first pull request 我信了
small fixes
delete node_modules
add mock data API in app.js. change API host in service.js to 127.0.0.1:8000 to use mock API
add some test data
bug fix for check if node is a lesson
[Zhenghan] badge notification completed, bug fixed
add proxy to node server and change host in service.js to local host.
Next, change all jsonp in service to get
all jsonp changed to get
add some mock user_data api. and a mock user_data delete api: curl -d "action=delete_all" <host>:<port>/exercise/v1/user_data/*
[Zhenghan] test system (incomplete)
[Zhenghan] test system (incomplete)
[Zhenghan] test system
Merge pull request #12 from zhzhang2012/master

[Zhenghan] bug fixed, test system
[Zhenghan] notification library
Merge pull request #13 from zhzhang2012/master

[Zhenghan] notification library
so called css fixed