add environment variable to control daily restart behavior
tweaks to wubot-reactor

 - environment ariable to control daily restart

  - increase reactor warning time to 5 minutes
    - also set noforward flag on reactor warning message
      as that can lead to a major flood of messsages when
      a machine reconnects after being offline a few days.
tweak default age colors

Extend colors to work better over a longer time span.

Also resolve an error in a logger statement.
include URL in WebFetcher error message
catch reactor errors in run_plugin()

Log, but do not die on a reactor exception.

Also a very minor doc tweak and whitespace adjustment.