fix the issue brought by 0.10.0 that Spring related classes are mistakenly loaded via DefaultInjector, which causes exceptions when there is no Spring libraries available.

fix auto update not triggered issue when there are same keys in different namespaces and the one with high priority deleted

2. adjust client side's long polling timeout from 600 seconds to 90 seconds

2 抽离了一个公共父类ApolloProcessor，用来处理反射相关的逻辑。 ApolloJsonValueProcessor,ApolloAnnotationProcessor,SpringValueProcessor都继承它
3 在PropertySourceProcessor中注册自动更新的监听器AutoUpdateConfigChangeListener
4 SpringValue增加isJson字段，表示这个属性是否是Json类型的
5 增加了单元测试

2. Support XML config placeholders
3. Add more tests to cover all kinds of cases
4. Update apollo demo to adapt for auto update functionality

2. Reorganize the feature to provide the ability to inject apollo
configs in Spring Boot bootstrap phase
3. Add more integration tests to cover different scenarios
4. Update apollo-demo to show this apollo bootstrap config feature could
be used with @ConditionalOnProperty

1. Enable config cache to improve config service performance, just set
config-service.cache.enabled to true in ServerConfig
2. Normalize the namespace name in case the one provided has character
case issue

add comment why PropertySourcesProcessor implements BeanFactoryPostProcessor instead of BeanDefinitionRegistryPostProcessor

1. add log output to console for config and admin service
2. remove dev, lpt, tooling logic
3. add default 2 seconds of initial delay to long polling

1. make ApolloAnnotationProcessor run as late as possible
2. make PropertySourcesProcessor run as early as possible
3. fix PropertySourcesProcessor initialization logic to support multple
Spring contexts