Users management design.

[hyperchi]

@qiuzhihui @Jelly-Yu
This is sth I will do by the end of next month I mean March or early April. If you guys wanna do also fine.
We need a user management feature later on.

1. Set up user login feature
2. User management page to change each users' info.
3. User register, email notification.
   There would be a top bar in each page for users, we will need profile management.
   new pages
   login register reset_pwd user_management

Several tech needed. Ajax call. User pwd MD5 hash. Email part? have no idea right now.

table 'users' required fields.
I would personally maybe prefer all varchar except id date

1. id int(10)
2. username varchar(20)
3. password varchar(20)
4. email varchar(30)
5. birthday date default null
6. register_ts date default null
7. gender varchar(10)
8. score int(10)
   if we need more comment. make sure these are not sth we'r going to alter in the future. Alter field would be painful.