Add various auto replay options:
 - All logs since the final client disconnected
 - All logs since the most recent client connect/disconnect
 - All logs since *you* last sent a message
 - All logs since X seconds ago (already implemented)
 - All logs since the current client last disconnected (track clients with some special token the client auto sends on connect)

Might need to #include <limits.h> in blabouncer.c to make some operating systems and/or compilers happy.

Send a PING to the server before assuming a timeout is definite.

Implement daemon (background) mode.

Implement BLABOUNCER EXIT command.

Some text gets written to previous debug.txt upon startup (getconfstr() output).

Don't exit if there's a failure to read the replay log file/line.