Fixed selecting required packages (openssh, SuSEfirewall2) in case of default configuration + minimal sw selection

- Packages are now requested always
- Opens/closes ports as requested by user
- bnc#893126
- includes a little refactoring
- no test case, that require to put everything into lib/network (in TODO)
- tested in production

I'm not sure if I understand the benefit about changing the value explained by @kobliha. But I agree with @lslezak that is safer against typos. I buy it :-)