[#1635] Use option 51 in conjunction with class triplet

Added a ChangeLog entry

doc/examples/kea4/all-keys.json
doc/sphinx/arm/dhcp4-srv.rst
    Updated doc

src/lib/dhcpsrv/alloc_engine.*
    AllocEngine::getValidLft() - revamped to apply use class
    triplet with option 51

src/lib/dhcpsrv/tests/alloc_engine4_unittest.cc
    TEST_F(AllocEngine4Test, getValidLft4)  - udpated
    to match new logic

1 files changed, 6 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index eb0bf9ebb0..55b64ea5bb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+1869.	[func]		tmark
+	Kea-dhcp4 now supports specifying valid-lifetime in client
+	classes.  Prior to this it could only be specified at the
+	global, shared-network, and subnet scopes.
+	(Gitlab #1635)
+
 1868.	[func]		andrei
 	The forensic log hook library has gained an auto-increment
 	primary key column in it's logs table. It is now able to function