v0.22-beta.2

• Allow comma-separated IPv4 addresses and ranges in ip pool and ip nat pool; pass multiple ranges through DHCP, NAT, and running-config.
• Add update channel release|pre to select stable or pre-release updates. update and update autocheck follow the selected channel.
• Add update autocheck and no update autocheck to check for and offer updates when an administrator first logs in after startup.
• Add banner startup and no banner startup to control the pre-login console and SSH banner.
• Fix CLI prompt suffixes and invalid-input marker alignment, including service-policy mode.
• Document the minimum CPU requirement: one core and two threads.