GitLab

 Replaced underscores with hypens in D2 config in remaining files:

    doc/examples/ddns/sample1.json
    doc/examples/ddns/template.json
    doc/guide/ddns.xml
    src/bin/d2/tests/d2_process_tests.sh.in
    src/bin/keactrl/kea.conf.pre
    src/bin/keactrl/tests/keactrl_tests.sh.in

Also, renamed interface-config to interfaces-config (plural form).

 - logger names are now kea-dhcp4, kea-dhcp6, kea-dhcp-ddns
 - fix in keactrl_tests
 - User's Guide, examples updated

There is a new function used in keactrl tests which waits for the server
to shutdown, rather than check if it is down already. This is to avoid
race condition when the process may not completely terminate when we
check that it is.

- Renamed kea4 and kea6 parameters to dhcp4 and dhcp6
- Location of the kea binaries is specified in the keactrl.conf
- Swap pools and subnets in kea.conf.
- Renamed keactrl commit command to reload
- Added -s and -c command line options.