core file highlight

[Dmitry Alexeyev <dmi_a qnx org ru>]

Hello! 

MC highlights file `core' dark brown. Everybody got used to it, so 
nobody notices. 
But! I am repairing a hacked box, there was directory named `core', in 
which exploit + setuid shell was hidden. 

Maybe it is good idea to highlight directory `core' with some specific 
color? I thought it is file before I looked into it from the shell... 

WBR,
Dmitry