Merge remote-tracking branch 'upstream/master'

Merge remote-tracking branch 'upstream/master'

* upstream/master: (68 commits)
  [CritFix] Fix unencrypted passwords processing in the controller
  [Feature] Add reading scripts for master connection
  [Feature] Add parsing scripts for master connection as well
  [Feature] Add configuration knobs for in and out parser scripts
  [Feature] Add lua utility to decode URL encoding
  [Fix] Fix secure_ip setting in controller
  [Fix] Fix adding maps from ucl
  [Doc] Update whitelist documentation
  [Feature] Add 'blacklist' and 'strict' modes for whitelists
  [Minor] Add missing file to the spec
  [Feature] Use generic global string split function
  [Fix] Link lpeg to rspamd lua library
  [Feature] Use universal redis definitions in rspamd plugins
  [Feature] Add universal function to parse redis servers for plugins
  [Feature] Add execution of lua global functions script
  [Feature] Allow static lua files in any parts of rspamd sources
  [Fix] Fix substring search when there are '\0' in strings
  Correct migration.md, small change to writing_rules.md
  [Fix] Try to fix proxying of stupid spamc protocol to HTTP mirrors
  [Fix] Handle log pipe read errors
  ...