-revision prints.c and other print files
-revision of the user's options names
-make structures/functions for dynamic structures
-enable filtering of encapsuled protocol headers (like IP header in ICMP) 
-options to display detailed layer protocol description
-use sprintf instead of fprintf in prints.c
-revision of filter.c to be flexible as protocol.c
-complete verification of the arguments in the check_options
-give the choice of the interface
-make a session layer filter
-stack for the received packet, keep the times
-time received options 
-ntohs / ntohl
-make the filter work for fragmented data (tcp,ip) 
-make the code fit correctly on a 80x24 console

-code optimization
-comment
-make the net libs
