Include: fixed assertion fail caused by missing initialization (bug surfaces only for stored binaries).

Sieve-filter: removed unnecessary MAILBOX_TRANSACTION_FLAG_REFRESH flag for mailbox_transaction_begin().

Restructured store action implementation to properly handle an attempt to store (keep) a message in the folder it originates from.

Testsuite: added tests on the envelope of outgoing messages produced by redirect, enotify:mailto, reject and vacation.

Major rework of envelope address handling: a normalized version of the envelope addresses is maintained in the message context and message context is now also available during action execution.

Removed the sieve-filter tool from the default build. Need to specify --with-unfinished-features to get this tool built.

Added compilation support for ereject extension. It is unfinished right now and performs exactly the same action as reject.

Testsuite: added tests for envelope/address test behavior with non-existant subaddress :detail part.

Envelope: fixed bug in application of address parts; failure to obtain the part would cause inappropriate match success (bug reported by Ron Lee)