Underfed 0.3.1

• A watcher started within 15 minutes of the host booting reads the channel chains at once.
  It measured their age from a monotonic clock that starts at boot, with zero as "never
  read", so on a fresh host the first read waited until the clock passed 15 minutes, and
  until then every starving channel was skipped with "no source after this one". The CI
  runners, freshly booted, showed it in the 0.3.0 tests.

Commits:

• 4209589 Read the chains at once when the watcher starts on a freshly booted host