Included scripts now execute in the context of the inner parent foreverypart loop.

For some inapparent reason it was not included in the output tarball.

An empty string yielded an empty string rather than "0".

The free handler of code dumper extensions was never executed.

Needed for test suite.

When the program crosses the boundary of the current jump somehow, the program is terminated and a corruption error is returned.

lib-sieve: mime/foreverypart: Fixed code dumping of `:param' argument. It erroneously reported a code corruption.

lib-sieve: Created special stringlist class for message headers, so that header names can also be returned by the iterator.

lib-sieve: Moved handling of implicit keep during multiscript execution outside the script sequence itself.
Before, implicit keep was executed as part of the final script execution. This caused the implicit keep to be executed as part of that script, including global context.
This caused insignificant errors during delivery to be logged as errors in the administrator log when the last script is global.

This makes this available for other extensions.

These will influence some of the performed tests.

doveadm sieve plugin: Added proper handling of Sieve storage initialization failure occurring when sieve_enabled=no

This allows completely disabling Sieve processing for a particular user.

It now extracts bare text from HTML/XHMTL parts.
Other text/* parts are still returned as is. Any other unrecognized content types are skipped.

This allows setting the MAIL FROM of the SMTP envelope for the notification e-mails.
The syntax is identical to the sieve_redirect_envelope_from setting.