sometimes route table may not be updated in time, so some dead nodes are still showing in the peer list.
when generating ipv4-peer table, we should avoid these dead devices overrides the entry of healthy nodes.
This patch implements:
1. A dns server that handles .et.net. zone in local and forward all other queries to system dns server.
2. A dns server instance which is a singleton in one machine, using one specific tcp port to be exclusive with each other. this instance is responsible for config system dns and run the dns server to handle dns queries.
3. A dns client instance that all easytier instance will run one, this instance will try to connect to dns server instance, and update the dns record in the dns server instance.
this pr only implements the system config for windows. linux & mac will do later.
* optimize memory issues
1. introduce jemalloc support, which can dump current memory usage
2. reduce the GlobalEvent broadcaster memory usage.
3. reduce tcp & udp tunnel memory usage
TODO: if peer conn tunnel hangs, the unbounded channel of peer rpc
may consume lots of memory, which should be improved.
* select a port from 15888+ when port is 0
icmp/udp proxy do not rely on kernel net stack, but currently not handle ip fragmentation correctly.
this patch add ip resembler to merge fragmented ip packet for udp/icmp proxy
* use correct i18n hook
* fix peer rpc panic
make sure server use correct transact id
* fix dhcp
recreate tun device after ip changed
* use upx correctly
* compile arm & armv7
* prepare to release v1.1.0
* correctly set mtu, and allow set mtu manually
* communicate between enc and non-enc should not panic
* allow loading cfg from file
* allow change file log level dynamically
Sijie.Sun