Wrong assumptions about logger is causing runtime crashes

[osa1]

If we use -fdebug but don't set DEBUG env variable(for debug level) or set it to 0, maxLvl is set to 0 in Control.LVish.SchedIdempotentInternal.new, and it doesn't create a logger since no logging should be done with that level. However, other parts of the library assumes that if -fdebug is used, that we have a logger in use and they do non-exhaustive pattern matching on the logger. (example: Internal.Control.LVish.SchedIdempotent.logStrLn)

This is causing runtime crashes and should be fixed.