Something I wasted 3 days on

Created by: clusterfack

show_message was using a message limit cap which was being flouted by bicon which encodes image data into a long string, a string so long that it would overflow that max message limit size and the rest of the message would be cut off by the internal sanity of show_message.

I don't even feel satisfied, this was a stupid bug.

Fixes #10002 (closed) Fixes #10171 (closed)