Fixed bug in the derivation of the binary path from the script path. A bare filename would yield a path relative to root.

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.