Capture corrupted binlog events

This toplevel ticket captures work related to binlog corruption. Broadly speaking, there appear to be four paths forward, three on the server and one in the client. On the server, we could (1) implement sandboxing for plugins (Andrei's comment "prevent faulty plugins"), (2) prevent binlog corruption from occurring, (3) warn when binlog corruption occurs (e.g. by detecting possible binlog corruption with timestamp checks as described in the ticket). On the client, we can find traces of corruption (some minimum length string of null bytes) enabled a new commandline option.