GitLab

Listed all loggers and updated the introductory text.

Also, revised the debug levels for all messages in the Dhcp4Srv class.

The output contains client identification information, such as
hw address, client id and transaction id.

    Adds bad-packet logger to DHCPv4 server

Objects passed by reference and todo instead of TODO.

Fixed, copyrights, typos, minor clean up items

doc/guide/logging.xml - added new logger description
src/bin/dhcp4/dhcp4_log.cc - added bad_packet logger and log name declarations
src/bin/dhcp4/dhcp4_log.h - added bad_packet and log name externs
src/bin/dhcp4/dhcp4_messages.mes - changed drop and NAK message identifiers
src/bin/dhcp4/dhcp4_srv.cc - changed packet drop and NAK log invocations
src/bin/dhcp4/main.cc - used extern for log name

- Enabled log messages in user_chk
- Fixed a typo