修改BNF

git-svn-id: https://qlanguage.googlecode.com/svn/trunk@208 6d982bb3-a5a7-393d-ffc5-582415be9c85
1.删除一个没用的变量
2.修改TestCase

git-svn-id: https://qlanguage.googlecode.com/svn/trunk@209 6d982bb3-a5a7-393d-ffc5-582415be9c85