On Windows it still prints to console, however (without timestamps).
Note that syslog mode doesn't produce any debug output even if -d is
specified (at least on macOS) -- probably the sysadmin needs to
enable debug logging.
- Util::RunInThread to run a lambda in a thread
- App exit handling cleanup
- EXMgr uses an id for clients now
- EXMgr keeps track of lagging clients
- EXMgr more aggressive with reconnects if no valid exclients
- Nits and refactorings and misc. cleanup
- Already supports listening on as many sockets as you wish
- Each listening server has its own thread
- Will implement later: SSL server
Also refactored code a bit, created the generic "Controller" class, made
EXMgr and SrvMgr inherit from it.
ToDo: Figure out workflow for connections and clients, model client
sessions, etc.
- Only send server.ping on idle >1min (previously we sent
unconditionally once a minute)
- Added __attrubute__ format stuff to the printf-like log functions
- Small nit
