Persistent IP-bans

[ohlidalp]

This is hopefully simple enough to just work.

Related to #93 but only persists existing bans, no extensions were added yet.

UPDATE: Tested and ready.

[CuriousMike56]

Some testing:

Created an empty official.blacklist file, added blacklistfile = official.blacklist to the server config, server reports:

25-09-2019 14:15:52|t01| WARN|Couldn't parse blacklist file, messages:
�,�U

I banned a client running a fresh config, blacklist now contains:

{
	"bans" : 
	[
		
		{
			"banned_by_nickname" : "CuriousMike",
			"ip" : "",
			"message" : "test",
			"nickname" : "Player"
		}
	]
}

No IP is written & the user is still able to join. A default blacklist (with name server.blacklist) should always be created if it doesn't exist.

[Zentro]

Add strncpy(b->ip, ip_addr.c_str(), 16); to the sequencer RecordBan. Without it, no IP is written to the blacklist file.

The blacklist file not being able to be parsed is due to an empty blacklist file.

[ohlidalp]

@CuriousMike56 thanks for testing, fixed.