move sql into model
Merge branch 'thy' into dev
merge
Merge branch 'dev' of github.com:JYWa/teamstyle16 into dev

Conflicts:
	application/views/forum/thread.php
merge thy
Merge branch 'dev' into thy
增加了验证码功能
tiny bugs
throw all session into models
Merge branch 'thy' into dev
rewrite the forum model
修改了threads 的view，需要注意的是php标签要写成 <?php ?>
fix forum
完成部分错误信息