Significant updates

digestion and parcels are now hard dependencies.

The awk approach to handling Mailman digests is now deprecated and
removed.

Revamping Mailman filter with external digestion

Fix pattern for author name in mailman digest summary

AO3 mail can include multiple updates, so change the footer pattern

In addition to CVE numbers, debian mail can include Debian Bug numbers

Re-adding 'dim' ANSI code

Change to handling header section of debian mail

Initial commit