Date Based File Archiving

Hello,
I've implemented a change that allows archiving based on dates instead of rolling/sequential numbering.
My changes should have minimal impact and works with the existing code/parameters as much as possible.
I've seen several posts asking for such functionality in my research and is something I wanted as well.
Let me know if this is acceptable, or if you have any comments/suggestions.

Thanks!
 - Mike

Commit log:
archiveNumbering can be set to Date.
archiveFileName should contain the standard {#} placeholder for numbers which will now be used to store the archive date.
archiveDateFormat can optionally be specified for a custom date format.
maxArchiveFiles will be honored and old files deleted when applicable (based on archive period)