Release 1.2.3

Release 1.2.3

* New DCC module (by @smfreegard)
* Rework whitelist module:
	- Now we check different elements for different checks
	- MIME from for DMARC
	- DKIM signature domain for DKIM
	- SMTP from or HELO for SPF
* Fix regexps results combination (*critical*)
* Fix issue with expressions processing (*critical*)
* Optimize strlcpy for aligned input
* Add support of half-closed connection in lua_tcp
* Allow to print compact json in client
* Save required score in history (#581)
* Allow to attach file descriptors to control commands
* Allow to send descriptors from workers to main
* Allow to attach fd when broadcasting to workers
* Implement log pipe feature for rspamd logs analysis
* Add `log_helper` worker
* Add `URIBL_SBL_CSS` (by @smfreegard)
* Add worker scripts functionality
* Add on load hooks for rspamd_config
* Add lua scripts for log_helper worker
* Add generic maillist detector (#584)
* Implement FANN autolearn using log_helper worker
* Rework metrics configuration to allow includes
* Change default value of forced removal in composite rules
* Allow to use assembly version of blake2b on x86 cpu
* Use less precise (but faster) clock if possible
* Insert redirected URL to the urls list
* Allow to get and set callback data for rspamd symbols
* Add binary heap implementation
* Use binary heap for expire algorithms in the hash
* Use `least frequent used` expiration strategy
* Allow to get mime headers from a task
* Add support for mime headers in `regexp` module
* Update Exim patches (by @fatalbanana)
* Allow building rspamd with jemalloc
* Save multipart boundaries
* SA plugin changes:
	- Properly handle MIME headers
	- Fix eval:check_for_missing_to_header rule
	- Implement SA compatible body regexps
	- Use sabody rules in SA plugin
* LUA API changes:
	- Add util.get_ticks function
	- Add util.stat function
	- Add task:get_symbols_numeric method
	- Add method to get number of symbols in the cache
	- Add lua methods to get redirected urls
	- Allow to get callbacks for lua symbols
	- Add config:set_symbol_callback function

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