修正编译时老提示GBK字符错误的问题
在帖子列表的actionbar增加回复帖子按钮和回复帖子对话框（功能未实现）
将项目编码由系统改为UTF-8
实现基本的回复帖子功能
Add gallery mode for images

* Add clickable ImageSpan
* Support multi-touch for images
Tweak order for constructors
Fix: drawer's avatar is not circle

Due to #2
Merge pull request #5 from allenz8512/feature

Feature