Tests do not exit, if actors are still active

[harrah]

Testcase: https://github.com/gerdriesselmann/sbt-actor-object-testcase

If there are started actors and sbt test is run, sbt will not terminate until every actor is terminated. sbt therefore runs forever.

This worked perfectly fine in sbt 0.7.

[harrah]

IMPORTANT This project has moved to https://github.com/sbt/sbt. This issue still exists to avoid dead links, but GitHub limitations prevent the original issue from being correctly preserved here. Please see sbt/sbt#497 for the full issue and to comment.