GitLab

 - Pkt4, Pkt6 classes now have descriptions
 - Many descriptions updated in Pkt class
 - Pkt::addOption() moved back to Pkt (from Pkt6)
 - DEFAULT_ADDRESS{,6} are now in private namespace.
 - copyright updated

 - Logging section updated.
 - Missing coma in kea.conf.pre added
 - ${localstatedir}/log is now created

Conflicts:
	src/lib/dhcpsrv/tests/daemon_unittest.cc

This change affects many files using the Configuration object and types
derived from it.

Comments have been improved in one file.  The other contains a test
that alters logging, so a test fixture has been added that ressets
the logging back to the default in its destructor.

Recently the "pool" parameter has been renamed to "pools" and its type
was changed from the string to a map. The kea.conf was not updated to
use the new format for the pool definition. This change corrects it.

Some unit tests in dhcpsrv altered the logging configuration but
never reset it. That configuration was then used for subsequent
tests and made them overly verbose.

Previously, the logger configuration was applied (to log4cplus) as soon as
it was parsed. We decided in the jabber discussion that the logger
configuration should only be applied if the whole configuration goes
through. So, the logger configuration is now 2-stage: parsing and commit
as for other configuration parameters.