* Extract createComment

* fix lint

* fix lint

* Avoid re-issuing redundant cross-references.

* Remove unused func; fix lint

* Simplify code as suggested by @laftriks

* Update test

* Add close/reopen from comment functionality

* Fix comment

* Rewrite closing/reopening template

* Check xref permissions, move action to services/pull

* Fix RefIsPull field

* Add xref tests

* Fix xref unique filter

* Only highlight keywords for actionable xrefs

* Fix xref neuter filter

* Fix check return status

* Restart CI

* Add a markdown stripper for mentions and xrefs

* Improve comments

* Small code simplification

* Move reference code to modules/references

* Fix typo

* Make MarkdownStripper return [][]byte

* Implement preliminary keywords parsing

* Add FIXME comment

* Fix comment

* make fmt

* Fix permissions check

* Fix text assumptions

* Fix imports

* Fix lint, fmt

* Fix unused import

* Add missing export comment

* Bypass revive on implemented interface

* Move mdstripper into its own package

* Support alphanumeric patterns

* Refactor FindAllMentions

* Move mentions test to references

* Parse mentions from reference package

* Refactor code to implement renderizable references

* Fix typo

* Move patterns and tests to the references package

* Fix nil reference

* Preliminary rendering attempt of closing keywords

* Normalize names, comments, general tidy-up

* Add CSS style for action keywords

* Fix permission for admin and owner

* Fix golangci-lint

* Fix golangci-lint

* Update ref comment

* Generate comment on simple ref

* Make fmt + remove unneeded repo load

* Add TODO comments

* Add ref-check in issue creation; re-arrange template

* Make unit tests pass; rearrange code

* Make fmt

* Filter out xref comment if user can't see the referencing issue

* Add TODOs

* Add cross reference

* Rearrange code; add cross-repository references

* Striketrhough obsolete references

* Remove unnecesary TODO

* Add "not supported" note

* Support for edits and deletes, and issue title

* Revert changes to go.mod

* Fix fmt

* Add support for xref from API

* Add first integration test

* Add integration tests

* Correct formatting

* Fix add comment test

* Add migration

* Remove outdated comments; fix typo

* Some code refactoring and rearranging

* Rename findCrossReferences to createCrossReferences

* Delete xrefs when repository is deleted

* Corrections as suggested by @lafriks

* Prepare for merge

* Fix log for errors