Extend DHCP server with Option 82 matching support

[troglobit]

Introduction

This task defines DHCP server support for setting up a single device with "DHCP IP-per-port" functionality.

This task depends on #703 and #438

Prerequisites

• Basic DHCP server support #703
• Add DHCP relay agent, with Option 82 support #438

Requirements

1. Extend static leases matching with support for Option 82
2. Add a preempt feature to dnsmasq whereby a lease can be "interuppted"¹ and handed out to anyone matching the static lease

Footnotes

1. A lease is usually guaranteed for the lifespan, or at least have the lease time, with lease preemption a device replacement is quicker since it does not have to wait for an old MAC address to time out. ↩