Compression Added

I received a code contribution for the TimeAndSizeRollingAppender from Eduardo Simioni, providing two new features:

1. Backup log files can be compressed.
2. The scavenger thread that deletes older files can be configured not to run, thereby conserving resources whilst allowing a virtually unlimited number of backups.

I've extended the contribution to support both GZIP and ZIP via configuration. Obviously you can use only one compression algorithm at a time. New source and binaries available in the usual place.