init typography

移动修改了util中的text-overflow和hide-text
Merge pull request #1 from ecomfe/master

merge
增加all.css，和几个排版相关的mixin，以及变量default-font-size
增加新的typography mixin
fix bug
更新typography，并增加样例
Merge branch 'master' of https://github.com/ecomfe/est into ecomfe-master

Conflicts:
	src/variables.less
Merge pull request #3 from zmmbreeze/master

增加typography模块和example