[server] New strategy for the log_module 

Hi Michael,

I have done some changes to update the log module so that we can remove the checks against the verbose context variable.

There are some places where I have leaved __fprintf(stderr__ since I was not sure about the behaviour to use ; I mean log the message to STDERR and syslog or only to STDERR ; Same with some uses of STDOUT.

I am now thinking a VERBOSE configuration variable could be added to fwknopd.conf. Any thoughts ?

mrash/fwknop#88