This makes the use of compound literal explicit.

Dovecot core doesn't have copyright notices in header files.

Now using struct smtp_address rather than sieve_address.
In some cases, struct message_address may prove to be more suitable, but this is the best fit for now.
Adjusted to the renamed fields in struct mail_deliver_context.

For accounts that perform many redirects, the lda-dupes database could grow to impractical sizes.
Changed the default retention period from 24 to 12 hours.

Implmented reporting full Pigeonhole version with hg tag so that builds between releases can be distinguished.
Copied from Dovecot for the most part.

This puts the ".sieve" and ".svbin" file extension definitions in a single locatio.
IMPORTANT: this fixes a bug in the include extension that implicitly mapped script names like "name.sieve" to "name".