hcz  增加 商家注册和登陆   2014/07/05
PS：商家登陆需修改 因为商家用户名不唯一，改登陆参数或者让用户名唯一
Merge branch 'master' of https://github.com/TuanFou/TuanFou.git

Conflicts:
	src/com/tuanfou/dao/MerchantDao.java
	src/com/tuanfou/service/MerchantService.java
	src/com/tuanfou/test/MerchantDaoTest.java