v0.5.0

Changelog

• 73361e8 fix: read the clock-check interval before starting the goroutine, which a test could race
• 329f16b docs: changelog for 0.5.0
• aa8de14 docs: describe the approval limits, the wall-clock deadline and the foreground rule
• a564495 fix: limit waiting devices per address and forget leavers, quiet waiting page, wall-clock deadline, drop typed-ahead input
• c0aaf38 docs: document --for and --approve
• e02bdf7 feat: --approve asks the owner before each new device gets in
• 1e8e442 feat: --for stops sharing after a set time; split run into small steps