Fixes argument list too long error.

This allows passing passdb variables. They are prefixed with forward_ when
imported to extra fields.

Upon login success, the next line was erroneously skipped.

Fixes:

Panic: file istream-crlf.c: line 24 (i_stream_crlf_read_common): assertion failed: (ret != -2)
Panic: file istream.h: line 228 (i_stream_read_more): assertion failed: (ret != -2)
(various other similar panics are possible)

This prevents startup failures if ssl_ca has a large number of certificates.

lib-sieve: sieve-result - Fix panic occurring upon temp fail after committed keep-equivalent action.

The determination of whether a keep-equivalent action was already executed is
performed in sieve_result_implicit_keep_execute(), which can also be called from
sieve_result_implicit_keep_finalize(). But there, the keep-equivalent status was
checked before any call to sieve_result_implicit_keep_execute(), which would
thus yield the wrong result.

This change also makes the associated debug message more specific (otherwise two
identical debug messages are logged) and an assert is added that makes sure the
keep-equivalent action is actually finalized when the implicit keep was supposed
to be finalized.

Panic was:

Panic: file sieve-result.c: line 1706 (sieve_result_implicit_keep_finalize): assertion failed: (aexec_keep->state == SIEVE_ACTION_EXECUTION_STATE_EXECUTED)

lib-sieve: sieve-result - Indicate in sieve_result_transaction_finalize() debug message whether actions were committed.

lib-sieve: sieve-result - Indicate in sieve_result_transaction_execute() debug message whether actions were executed.

lib-sieve: sieve-result - Assert that implicit keep is executed in sieve_result_implicit_keep_finalize().

lib-sieve: sieve-result - Fix resource leak occurring when implicit keep is executed before temporary failure at commit.

In the commit phase the implicit keep was never finalized, meaning that it was
not rolled back and thus not cleaned up properly. This leads to a memory leak
and a mailbox reference leak. This in turn causes an assert crash at the end
of delivery when the mail user is destroyed.

It will be executed in the commit phase if necessary; don't do it early; it will
only be rolled back.

lib-sieve: sieve-result - Move temp failure status checks into sieve_result_implicit_keep_finalize().

lib-sieve: sieve-result - Move temp failure status checks into sieve_result_implicit_keep_execute().