Refactor annotation config

NPE bug fixed.

Feature: support specify ip & port registered to registry from environment properties 

Optimize zookeeper block logic on app startup 

* 增加MethodValidated注解的测试用例  及对MethodValidated使用场景和用法的说明注释

* 将需要检查的分组维护到List<Class<?>> groups中，包括当前接口类及Default.class两个默认的分组

* 修改接口级别为jdk1.6; 按javadoc规范修改注释

 Adjust some config properties

Fixed #672: Monitor blocks when registry is unreachable (#777)

* Optimize(AbstractRegistry) registry cache, one registry file per 'registry & application', avoid reload (#685).

* Fixed #692 optimize zookeeper operation in service export/reference process: check already exists before create

Deprecate internal JSON impl and change to fastjson

The operator '+' has a higher operation priority than '?:'. A NPE will be thrown if getUrl() returns null, which is not expected.

fix the bug: cant enable override

合入hessian官方4.0.3部分源码，支持java.util.EnumSet反序列化

Fix 'start.sh' waits indefinitely when specified the 'dubbo.protocol.host' parameter

Optimize route: route on service level, then on method level

Fix class convert error in PojoUtils.relealize() when using fastjson serialization protocol during generic invoke

Fix typo implemention -> implementation

Simplify 'if(available == true)' with 'if(available)'

netty4 support

fix(SimpleMonitorService.java) int i = consumer.indexOf(':'); when consumer==null (#405)