mail/dovecot and mail/dovecot-pigeonhole upgrade to 2.3.5 and 0.5.5 respectively

dovecot changelog:
+ Lua push notification driver: mail keywords and flags are provided in MessageNew and MessageAppend events.
+ submission: Implement support for plugins.
+ auth: When auth_policy_log_only=yes, only log what the policy server response would do without actually doing it.
+ auth: Always log policy server decisions with auth_verbose=yes

• v2.3.[34]: doveadm log errors: Output was missing user/session
• lda: Debug log lines could have shown slightly corrupted
• login proxy: Login processes may have crashed in various ways when login_proxy_max_disconnect_delay was set.
• imap: Fix crash with Maildir+zlib if client disconnects during APPEND
• lmtp proxy: Fix potential assert-crash
• lmtp/submission: Fix crash when SMTP client transaction times out
• submission: Split large XCLIENT commands to 512 bytes per command, so Postfix accepts them.
• submission: Fix crash when client sends invalid BURL command
• submission: relay backend: VRFY command: Avoid forwarding 500 and 502 replies back to client.
• lib-http: Fix potential assert-crash when DNS lookup fails
• lib-fts: Fix search query generation when one language ignores a token (e.g. via stopwords).

pigeonhole changelog:
+ IMAPSieve: Add new plugin/imapsieve_expunge_discarded setting which causes messages discarded by an IMAPSieve script to be expunged immediately, rather than only being marked as "\Deleted" (which is still the default behavior).

• IMAPSieve: Fix panic crash occurring when a COPY command copies

messages from a virtual mailbox where the source messages originate from more than a single real mailbox.

• imap4flags extension: Fix deleting all keywords. When the action

resulted in all keywords being removed, no changes were actually
applied.

• variables extension: Fix truncation of UTF-8 variable content. The maximum size of Sieve variables was enforced by truncating the

variable string content bluntly at the limit, but this does not
consider UTF-8 code point boundaries. This resulted in broken UTF-8 strings. This problem also surfaced for variable modifiers, such as the ":encodeurl" modifier provided by the Sieve "enotify" extension. In that case, the resulting URI escaping could also be truncated inappropriately.

• IMAPSieve, IMAP FILTER=SIEVE: Fix replacing a modified message. Sieve scripts running in IMAPSIEVE or IMAP FILTER=SIEVE context that modify the message, stored the message a second time, rather than replacing the originally stored unmodified message.
• Fix segmentation fault occurring when both the sieve_extprograms

plugin (for the Sieve interpreter) and the imap_filter_sieve plugin (for IMAP) are loaded at the same time. A symbol was defined by both plugins, causing a clash when both were loaded.