* master: (22 commits)
  Extend Cluster Applications to allow installation of Prometheus
  Docs: move article LDAP-CE to its topic-related folder
  Improve performance of DiffDiscussion#truncated_diff_lines and DiffNote#diff_line by removing expensive diff position calculation and comparison
  Reverted fix https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/15788
  Execute project hooks and services after commit when moving an issue
  Use relative URLs when linking to uploaded files
  Use gitlab-styles
  Clarify Auto DevOps pipelines
  Make webpack fail for missing exports
  Update VERSION to 10.4.0-pre
  Update CHANGELOG.md for 10.3.0
  Explictly require Gitlab::Utils in ProjectFeaturesCompatibility
  Add note about using the term GPG for all related implementations
  Add index on namespaces lower(name) for UsersController#exists
  docs: fix a typo in LFS documentation
  Fix prometheus arg in prometheus.yml
  Update Dependencies
  It should escape spaces to %20 rather than +
  Replaced the remaining code-fork icons
  code-fork replacements
  ...