socat: enable help output on command line

$ socat -h
2014/07/07 11:59:10 socat[24013] E unknown option "-h"; use option "-h" for help

^ not very helpful

in socat.c:
 #if WITH_HELP
       case '?':
       case 'h':
            socat_usage(stdout);

so it turns out that --disable-help wasn't the best idea.
socat: fix for x-compile
add socat to world