Updates #2541. Updates #2834. Squashed commit of the following: commit d1580182db3b5866213e017405aa2cf8a6ee2f24 Author: Ainar Garipov <A.Garipov@AdGuard.COM> Date: Wed Mar 17 14:51:43 2021 +0300 all: doc changes; imp naming commit f036b50a60ba030aa6866944fc7a7b8776ce01d4 Author: Ainar Garipov <A.Garipov@AdGuard.COM> Date: Wed Mar 17 14:09:19 2021 +0300 dhcpd: fix static leases