[master] Remerge with 566

    Merge branch 'master' of gitlab.isc.org:isc-projects/kea

diff --cc ChangeLog
index e4cda7ae74a290708157549fffd63b62002db421,9113308fa0b441131971a4af3d4bca83bf764a81..c9a3f279e81263ddfe6539ad384fc75147fd19d9
--- 1/ChangeLog
--- 2/ChangeLog
+++ b/ChangeLog
@@@ -1,8 -1,8 +1,13 @@@
- 1560. [func]          tmark
++1561. [func]          tmark
 +      kea-dhcp6 now automatically deletes configuration elements
 +      that have been deleted from configuration backends.
 +      (Gitlab #566,!304, git 2e85376f1b57187b822c662144380e04372cffff)
 +
+ 1560. [bug]           fdupont
+       kea-dhcp4 now permits option code values of 0 and 255 for
+       options defined in option spaces other than the "dhcp4" space.
+       (Gitlab #564,!300, git 7a0a0b84d91893f08c0ee6f236daa05bede65166)
+ 
  1559. [func]          fdupont
        Added DHCPv6 support to the MySQL Config Backend hook.
        (Gitlab #397,!244, git 980091ecd717e41a61f0d7f6808213e450647d8e)