Handle 404 gracefully and also handle unexpected error without dumping stack
Merge pull request #84 from cloudfoundry-incubator/Handle404

Handle 404 gracefully and also handle unexpected error without dumping stack
Take advantage of Thread.pass to make sure UI thread is not starved due to compute-intensive threads
Merge pull request #85 from cloudfoundry-incubator/ThreadPass

Take advantage of Thread.pass to make sure UI thread is not starved due to compute-intensive threads