kcptun-libev v2.3.2

Changes since v2.3.1:

1. [conf] Add config service_id to support multiple services in the same rendezvous server.
2. [server] Support changing the timeout by reloading the configuration.
3. [logging] Log timestamp format now conforming to both ISO8601 and RFC3339.
4. [util] If debug info is available, handle more signals and print the stack trace of the crash.
5. [build] More compiler optimizations.
6. [contrib] Sync upstream changes.

Build variants:

• -static: does not require the system to support dynamic linking.
• android, win32: requires only the dynamic libraries provided by the system.
• other: runtime dependencies should be installed.

Full Changelog: v2.3.1...v2.3.2