Issue: #2861

[Minor] Add "iso" to bad_extensions

Issue: #2857
Closes: #2857

[Minor] Avoid comparing string with boolean

[Minor] Fuzzy upstream error threshold config

when CT is not found

It would be nice to be able to configure `max_errors` and `revive_time`
for fuzzy check module for low traffic systems.

When traffic volume is relatively low an error rate builds at very slow
rate and it would take a while to reach default 40% threshold. At the
same time waiting for 60s sometimes could be unreasonable for dynamic
environments to re-resolve rspamd fuzzy storage.

* [Conf] Allow to load users plugins from plugins.d
* [Conf] oversign openpgp and autocrypt headers
* [Feature] Add SPF FFI library for Lua
* [Feature] Add more verbosity for SPF caching
* [Feature] Antivirus: Handle encrypted files specially
* [Feature] Clickhouse: Slashing - add new fields to CH
* [Feature] Dkim_signing: Add OpenDKIM like signing_table and key_table
* [Feature] Dkim_signing: Allow to use new options as maps
* [Feature] Import fpconv library
* [Feature] Lua_maps: Allow static regexp and glob maps
* [Feature] Parse ical files
* [Feature] Rspamadm: Add dns_tool utility
* [Feature] Store SPF records digests
* [Feature] Use fpconv girsu2 implementation for printing floats
* [Fix] Clickhouse: Use integer seconds when inserting rows
* [Fix] Fix floating point printing
* [Fix] Fix processing of embedded urls
* [Fix] Lua_clickhouse: Fix CH errors processing
* [Fix] Make spf digest stable
* [Fix] Properly detect encrypted files in zip archives
* [Fix] Slashing: Store times in GMT timezone in ClickHouse
* [Rules] Add additional conditions to perform BTC checks
* [Rules] Fix pay-to-hash addresses validation

Signed-off-by: Vsevolod Stakhov <vsevolod@highsecure.ru>

Issue: #2848

This reverts commit f803de985a.

Issue: #2848

[Minor] Improve mime_types plugin

[Conf] oversign openpgp and autocrypt headers

[Minor] unify rule scores and weights and improve descriptions

if detected MIME type differs from Content-Type header

* IsSpf
* MimeRecipients
* MessageId
* ScanTimeReal
* ScanTimeVirtual
* SMTPFrom - alias
* SMTPRcpt - alias
* MIMEFrom - alias
* MIMERcpt - alias

Added new values to DKIM/DMARC checks to indicate different failures.

merge upstream into local master

in filenames to improve file extension detection