add some exception tracing

Change-Id: If9f87137d86c2256430f4fbbf7c6a841be674449
SimpleFuture: cancels should trigger callbacks

Change-Id: I636f1f0f79401490b518ff26cba38d73bbca354b
Fix test
Fix test
Revert "SimpleFuture: cancels should trigger callbacks"

This reverts commit f0875c7505876e0467df7249af7d394dd2025113.
Fix test for adjusted cancel behavior
Revert "Revert "SimpleFuture: cancels should trigger callbacks""

This reverts commit ab932d94018a4deb1622917db72df6faa2ac6408.
SimpleFuture: calling setCallback on a cancelled SimpleFuture should invoke the callback.
Merge branch 'master' of https://github.com/koush/AndroidAsync

# By Koushik Dutta
# Via Koushik Dutta
* 'master' of https://github.com/koush/AndroidAsync:
  SimpleFuture: calling setCallback on a cancelled SimpleFuture should invoke the callback.
  Revert "Revert "SimpleFuture: cancels should trigger callbacks""
  Fix test for adjusted cancel behavior
  Revert "SimpleFuture: cancels should trigger callbacks"
  Fix test
  Fix test
  SimpleFuture: cancels should trigger callbacks
  add some exception tracing