Change Microsoft.AspNet.WebApi.Client => System.Net.Http.Json on netstandard

1. Filter unreleased namespace rather than warning log.
2. Wait until successful or timeout at startup if not local cache file.

Com.Ctrip.Framework.Apollo

1. IApolloOptions HttpMessageHandlerFactory => HttpMessageHandler.

Com.Ctrip.Framework.Apollo.Configuration

1. Mark ApolloOptions.HttpMessageHandlerFactory [Obsolete]
2. Add MelLogging, write apollo log to Microsoft.Extensions.Logging
3. Upgrade Microsoft.Extensions.* 2.1.1 => 3.1.0

Com.Ctrip.Framework.Apollo.ConfigurationManager

1. Mark ConfigUtil.UseHttpMessageHandlerFactory [Obsolete]

<add key="Apollo:EnablePlaceholder" value="true" />

要求运行时.NET Framework版本4.7.1及以上

• 添加功能强大的CommonSectionBuilder
• 删除Key2XmlConfigurationBuilder（请使用CommonSectionBuilder）
• AppSettingsSectionBuilder允许配置前缀
• ConnectionStringsSectionBuilder允许不使用前缀

具体请查看文档ConfigurationBuilder支持

Com.Ctrip.Framework.Apollo

1. 日志包含更详细内容

Com.Ctrip.Framework.Apollo.ConfigAdapter.Yaml

1. 更新YamlDotNet

Com.Ctrip.Framework.Apollo.Configuration

1. 完全禁用ApolloConfigurationManager

Com.Ctrip.Framework.Apollo.ConfigurationManager

1. 添加Key2XmlConfigurationBuilder和NodeReplaceSectionBuilder，方便直接替换节点内容
2. ConnectionStringsSectionBuilder支持读取特定的keyPrefix
3. ApolloConfigurationBuilder添加静态AppSettingsInitialized属性

1. 添加json、xml等格式的namespace的支持，并提供扩展接口
2. 重新设计IConfig，通过扩展方法实现更多功能
3. 重构日志，直接通过委托而不需要实现接口
4. Apollo.Configuration支持通过Env读取metaserver
5. Apollo.ConfigurationManager允许从环境变量读取apollo配置值
6. Apollo.ConfigurationManager添加对.net core风格key支持，优先级低于原来的key