Merge pull request supercollider#3648 from supercollider/3.9

Merge 3.9 into master

Merge pull request supercollider#3595 from supercollider/3.9

Merge 3.9 into master

Merge pull request supercollider#3497 from supercollider/3.9

Merge 3.9 into master

Merge pull request supercollider#3419 from supercollider/3.9

Merge 3.9 into master

Merge pull request supercollider#3387 from snappizz/topic/3.9.0-rc2

Update version number to 3.9.0-rc2

[3.8] Update changelog and version number for 3.8.1 (supercollider#3343)

* Bump version to 3.8.1

* Update changelog for 3.8.1

* Revise changelog for 3.8.1

* Revise changelog for 3.8.1

* Add LocalOut fix to 3.8.1 changelog

Create changelog_to_schelp.sh (supercollider#3363)

Merge pull request supercollider#3258 from supercollider/readme-3.9

Changelog - update description for 3.9