Sync Dev/3.2.1

add: support nutz mvc and nutz http

Update a comment

change: use ElementMatchers.takesArguments to match Sender(Request)

# Conflicts:
#	apm-network/src/main/java/org/skywalking/apm/network/trace/component/ComponentsDefine.java
#	apm-sniffer/apm-agent/pom.xml
#	apm-sniffer/apm-sdk-plugin/pom.xml

Sync Dev/3.2.1 to master

fixed the collector online/offline bug in zookeeper

change: using ContextCarrier.items() in 3.2.1-2017
remove: useless javadoc in nutz-plugins

support struts 2 plugin

use ConstructorInterceptPoint to get "org.nutz.http.Request",
and store in SkyWalkingDynamicField, then set header in SenderSendInterceptor

Merge branch 'feature/support-struts2-plugin' of https://github.com/ascrutae/sky-walking into feature/support-struts2-plugin

New Context Carrier CODING STYLE(API)

add auto local jar file installation before compile

Merge remote-tracking branch 'upstream/feature/new-context-carrier' into feature/support-struts2-plugin

The commit code in ClusterZKDataMonitor's 'process' method,fixed the collector online/offline bug. By 'client.getChildren\(event.getPath\(\), true\);', collector can't get the deleted node. In fact,ClusterZKDataMonitor listening zookeeper 'onNodeChanged' event by use 'if \(listeners.containsKey\(event.getPath\(\)\)\)'.

fix start failed issue

Update README_ZH.md

Update README.md