添加异常过滤配置，修改exception alert规则和alert report build规则，添加异常过滤文档说明，修改topreport visitor test case
Merge branch 'master' of https://github.com/dianping/cat
Merge pull request #318 from jialinsun/master

添加异常过滤配置，修改exception alert规则和alert report build规则，添加异常过滤文档说明，修改topreort testcase