Handle IPC_GAGLIST (19) messages

The server sends a list of gags that it supports when the client connects but webmw doesn't do anything with it currently.

["gag", "chef", "kraut", "fudd", "jive", "mirror", "latin", "censor", "wibble", "swab", "strfry", "tnarg", "furby", "warez", "duck", "saya", "bunny", "morse", "annoy", "french", "babel", "nosport", "martian", "hazelesque", "pklong", "unreturnable"]```