Add project id to watching message

We redefine watchingMessage in project scope so we can use
thisProjectRef to make the watching message more precise.

Fixes #2038

notes/sample.md

@@ -0,0 +1,12 @@
+[@dwijnand]: https://github.com/dwijnand
+
+[2059]: https://github.com/sbt/sbt/issues/2059
+[2662]: https://github.com/sbt/sbt/pull/2662
+
+### Fixes with compatibility implications
+
+### Improvements
+
+- Changes `publishTo` and `otherResolvers` from SettingKeys to TaskKeys. [#2059][2059]/[#2662][2662] by [@dwijnand][@dwijnand]
+
+### Bug fixes