Release 1.6.4

Release 1.6.4

* [Feature] Add method to get all content-type attributes in Lua
* [Feature] Add some sanity checks for actions and controller
* [Feature] Allow randomly select User-Agent from a list
* [Feature] Deal with obscured URLs with @ symbols
* [Feature] Milter headers: support adding/removing arbitrary headers from config
* [Fix] Add another workaround to display history properly
* [Fix] Add missing rspamadm control options to help
* [Fix] Auth-Results: Multiple DKIM signatures
* [Fix] Crash in URL processing
* [Fix] Default monitoring domain for surbl plugin
* [Fix] Detection of maillist optimized and fixed
* [Fix] Do not cache SPF records with PTR elements
* [Fix] Fix blacklists and DMARC in whitelist
* [Fix] Fix exceptions list in surbl
* [Fix] Fix processing of closed tags
* [Fix] Fix PTR processing in SPF
* [Fix] Lowercase HTTP headers to make them searchable from Lua
* [Fix] options.local_networks setting
* [Fix] Ratelimit: lowercase email addresses
* [Fix] Rebalance and slightly rework MX check plugin
* [Fix] Redis script loading in DMARC; URL tags; URL reputation
* [Fix] Reject invalid bh for DKIM signatures earlier
* [Fix] Remove incorrect method `task:set_metric_subject`
* [Fix] Rewriting subjects via force actions module
* [Fix] RPM postinstall
* [Fix] Treat 'rewrite subject' as spam action
* [Fix] Try harder to find urls
* [Fix] Use full URL when making an HTTP request
* [Fix] Use raw urls when sending requests to redirector
* [Fix] Use weight from map for fuzzy scoring
* [Rules] Penalise R_BAD_CTE_7BIT for utf8 messages

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