完成四个状态的按钮响应，剩余字符串的现实问题
almostly completed the showing of requests list
merge
Merge branch 'master' of https://github.com/jnuzh/BookShareClient

Conflicts:
	src/group/acm/bookshare/LoginActivity.java
	src/group/acm/bookshare/MainActivity.java
	src/group/acm/bookshare/function/Friend.java