rekey secrets.yml with a real password
add slave passwords for buildbot-linux4 and knuth
Fix bogus elements in weekly status email

Fixes #3083.
Merge pull request #27 from djmitche/real-secret-password

rekey secrets.yml with a real password
Merge pull request #28 from djmitche/nine-slave-passwords

Add nine metabuildbot slave passwords
Merge pull request #29 from djmitche/bug3083

Fix bogus elements in weekly status email
Set the root password

Very few people (OK, just me at the moment) have this password, as most
will access systems via sudo.  This will only be used for console access
when performing repairs.  The crypted password is stored in the secrets
file -- no need to rely just on crypt(3) for that.

Fixes #3004.