Fix telnet response to control functions
eggdrop is distinguishable from normal telnetd, because a normal telnetd will immediately respond to a telnet control function, and eggdrop wont. this is due to eggdrop's sockgets() looks for EOL \n / \r, and thus will respond to telnet control functions only after also a normal \n or \r message was received.
this also means, eggdrop's response to telnet control function is delayed and thus may render such function useless.
the code here is shared with 2 open pull requests, which should be reviewed/merged first: #593 and #610.
In short- need to fix telnet control response in 1.9, as it will affect the user-facing output an expect script could be relying on (unlikely, but still valid). Specific comment above applies:
"a normal telnetd will immediately respond to a telnet control function, and eggdrop wont. this is due to eggdrop's sockgets() looks for EOL \n or \r, and thus will respond to telnet control functions only after also a normal \n / \r message was received."