Merge pull request #12 from mtomaschewski/dhcp-request-1

dhcp4 request fixes 1
remove TODO file, moved to individual github issues
Remove newline from debug output in __ni_config_parse_ifconfig_source
Merge pull request #85 from olafhering/tweak_todo_list
Merge pull request #86 from olafhering/ni_config_parse_ifconfig_source-newline
dhcp6: fixed to accept low preference server offers

We wait until retransmit timeout before we accept
offers from low preference servers.
We may make it configurable how long to wait later.