Added aVERBOSE variable in fwknopd.conf

Hi Michael,

Here are some changes to add a VERBOSE variable to fwknopd.conf. The variable can be set as an integer value. The -v command line switches override its value when set in the configuration file.

It also updates the default verbosity for fwknopd from LOG_NOTICE to LOG_INFO as you suggested.

I think I may also have introduced an issue :

```
[Rijndael] [client+server] rotate digest file.......................fail (1)
[Rijndael+HMAC] [client+server] rotate digest file..................pass (2)
[valgrind output] [flagged functions] ..............................pass (3)
```
but I have not found the problem yet :)

I have read the fwknop tutorial and it looks great. I have noticed one or two wording mistakes, but that is it. I will be able to send you a tiny patch tomorrow since I have not my notes with me right now.

Regards,