Item12381: Improve bootstrap messages

Quiet the logs completely if TRAUTO is not enabled.

Bootstrap message indicates that the LocalSite.cfg could be missing or
damaged,  but Foswiki dies if LSC is damaged,  so simplify the
bootstrap message.  Also give more information about remaining logged in
until an admin user is established.

If ASSERTS are enabled, then warn if there are any issues when
processing the Config.spec files.  Otherwise, let spec issues pass,
though they may still crash when configure loads them.