Packets: Fix min_value / max_value boundary cases for Parse_(U)IntField

Scheduler: Add debug log message, fix signal handlin bug
Scheduler: Remove all registered handlers/callbacks/descriptors at end of unit test
Utils/Logger: Undef SENF_LOG_CONF if defined in main.test.hh
Scheduler: Moved Daemon class from Utils here. Can't be in Utils since it depends on the Scheduler :-(
Scheduler: Daemon class: Implemented correkt fork() and simple log-passing behaviour