基本完成部分特征选择功能：PCC、IG、柱状图、饼图
Merge branch 'feature_selection' into develop

Conflicts:
	veterans/index.html
	veterans/static/js/app.js
	veterans/static/js/directives.js
Merge branch 'develop' of https://github.com/yanshixing/dmss into develop

Conflicts:
	veterans/main.py