Correct the database tags of some backend housekeeping tasks.
Make MythFillDatabaseTask run if it missed its original run window.

This corrects an issue where MythFillDatabaseTask would never run if
performing its custom suggested time check and it had missed its
original window. This modifies the DailyHouseKeeperTask:InWindow
method to return true if it is beyond the initial window, but still
within the time frame limits set by 'MinHour' and 'MaxHour' database
settings.
Miscellaneous fixes.

Correct debug logging of task run probabilities.
Add RunProlog and RunEpilog to task thread.
Break SetHourWindow out into a separate method.

This breaks the method used to pull MythFillDatabase run window
restrictions and apply them to the task into a separate method. This
should likely be called any time we do a settings refresh, so these
settings can be changed without restarting the backend.