exec offline hook before unexpected exit

Disable stdout/stderr redirect to syslog

add custom online/offline hook cmd

Makefile: bump version

增加802.1X认证通过后MISC_START_ALIVE超时检查

删除procd respawn
恢复hotplug脚本并由hotplug等待网络联通后启动scutclient

scutclient v3.1

Retry when receive falilure from the server.
Build-in scheduled restart.(experimental)
Code cleanup.

scutclient v3.0

主程序删除对uci的依赖，目前可以在其他Linux发行版上正常运行。
OpenWrt启动脚本使用procd管理进程。

Release 2.2

Bump to 2.1

Bump version to 2.0