[Exim] exicyclog request

It would be highly desirable to see any compression tasks commence _after_
logfiles have been properly rotated.

Exicyclog first compresses exim_mainlog.01 before rotating exim_mainlog into
exim_mainlog.01. Machines at my site require up to or over an hour to
compress exim_mainlog.01 (uncompressed >1GB), resulting in exim_mainlog
being rotated at inconsistant times throughout the week. We've altered the
scripts here, but arguably this should be altered in the release too.

Cheers & thanks.