It was merged in release/scala-ide-3.0.x-juno, this pull request apply the changes to master.
We may want to ported to release/scala-ide-3.0.x and platform/juno too.
enable scala actions on Java projects in non-Java perspective
(cherry picked from commit 82e6b26)
Merge pull request #362 from skyluc/issue/java-project-actions-1001597
Put changes from pr #357 in the right branch