* origin/master: (21 commits)
  docs: removes notes about beeing introduced in 5.0
  lock caniuse-db version to resolve phantomjs rendering issue
  Update dashboard_permissions.md
  move database-specific code into dialects (#11884)
  refactor: tracing service refactoring (#11907)
  fix typo in getLdapAttrN (#11898)
  docs: update installation instructions targeting v5.1.2 stable
  changelog: add notes about closing #11862, #11656
  Fix dependencies on Node v10
  Update dashboard.md
  changelog: add notes about closing #10338
  Phantom render.js is incorrectly retrieving number of active panels (#11100)
  singlestat: render time of last point based on dashboard timezone (#11425)
  Fix for #10078: symbol "&" is not escaped (#10137)
  Add alpha color channel support for graph bars (#10956)
  interpolate 'field' again in Elasticsearch terms queries (#10026)
  Templating : return __empty__ value when all value return nothing to prevent elasticsearch syntaxe error (#9701)
  http_server: All files in public/build have now a huge max-age (#11536)
  fix: ldap unit test
  decrease length of auth_id column in user_auth table
  ...