Tweaks for oracle.
Revert to PickleType.
new callable
Merge pull request #1678 from limnick/master

fix old callable with new builtin callable
Use callable() now that it is allowed again (Issue #1678)
Implements task.throws.  Closes #1682
Tests passing
Events from clients now uses generated nodename "gen<pid>@<hostname>"
Adds Task.send_event for sending custom task events. Issue mher/flower#143
Worker: Changes order of startup so that Mingle -> Control -> Gossip.  Issue #1686
Fixes #1684
Fixes confusing argument errors for task decorator.  Closes #1692
Merge branch 'trevorskaggs/oracle-tweaks'
Django: Perform model validation on worker init.  Closes #1681
Import StringIO/BytesIO from io module
Fixed incorrect eta when countdown is used with timezone setting.
Canvas: Unroll groups with only one item.  Closes #1656
Fixes django tests
Forgot to push change for Issue #1656
Merge branch 'anti-social/fix_countdown'