release: Start preparation for 4.18.2

docs: added release notes for 4.18.2

descriptions: fixed rendering problem with certain meta-tags. - fixes #5587 - previously escaped values were used for pattern matching, we escape it again to bring old behaviour.

permissions: add better helper block about default permissions, and corelation with anonymous access.

mentions: markdown renderer now wraps username in hovercard logic allowing checking the mentioned user. - ref: #5586

Authentication: cache plugins for auth and their settings in the auth_registry. - Before that change on each requests 4x we loaded plugins for authentication, this hit many caches, db invalidation context and loaded the plugins logic each time. This was a heavy performance hit for SVN and other backends as they needed to load that plugins many many times - Since Authentication plugins almost never change, we'll not store the plugins listed for authentication into the authnregistry for each process - For AuthPlugins settings we now also flush plugins settings, and authnregistry cached plugins

flash: fixed display problem with flash messages on error pages.

docs: added note about hard restart due to celery update

emails: fixed some fonts rendering problems in outlook. - it's not perfect, but we're getting there...

emails: fixed bug in test email sending. - AuthUser instance was wrongly used for user who sent the email which we don't support

summary: fixed styling of readme indicator.

maintainance: run rebuildfncache for Mercurial.

Added tag v4.18.1 for changeset 71d8791463

release: Finish preparation for 4.18.1

release: updated pip2nix output for 4.18.1

release: Start preparation for 4.18.1

docs: added release notes for 4.18.1

issue-trackers: fixed missing save to get back to inherited settings.

ux: change file search to file content search which makes a better description of what we search for.

ui: improved readme rendering.