"[ESP111]<pre display>" show IP with <pre display> command
"[ESP111]" will show 192.168.x.xxx
"[ESP111]M117 " will show M117 192.168.x.xxx
"[ESP888]RESTART" will show RESTART and restart module
no filtering, command pass from SERIAL to TCP, and TCP to SERIAL, but
are also stored to check if there is a [ESPXXX]<param>\n where XXX are
command number and <param> is a sequence of parameters ended by a \n
