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Merge pull request #714 from XWB/deprecated

Deprecate CommentExtension::isCommentDeleted

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Update Changelog.md

Merge pull request #689 from XWB/changelog

Update changelog

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Prepare 2.2.0 release

Prepare 2.1 release

Merge pull request #626 from blankse/flat_view_async

Allows flat view for async thread