SchedulerDB bugs:
* Exception upon shutdown:

	Traceback (most recent call last):
	  File "/tools/buildbot-schedulerdb//lib/python2.5/site-packages/buildbot/process/base.py", line 442, in allStepsDone
	    return self.buildFinished(text, self.result)
	  File "/tools/buildbot-schedulerdb//lib/python2.5/site-packages/buildbot/process/base.py", line 475, in buildFinished
	    self.deferred.callback(self)
	  File "/tools/twisted-8.0.1/lib/python2.5/site-packages/twisted/internet/defer.py", line 242, in callback
	    self._startRunCallbacks(result)
	  File "/tools/twisted-8.0.1/lib/python2.5/site-packages/twisted/internet/defer.py", line 307, in _startRunCallbacks
	    self._runCallbacks()
	--- <exception caught here> ---
	  File "/tools/twisted-8.0.1/lib/python2.5/site-packages/twisted/internet/defer.py", line 323, in _runCallbacks
	    self.result = callback(self.result, *args, **kw)
	  File "/tools/buildbot-schedulerdb//lib/python2.5/site-packages/buildbot/process/base.py", line 208, in _release_slave
	    self.slavebuilder.buildFinished()
	  File "/tools/buildbot-schedulerdb//lib/python2.5/site-packages/buildbot/process/builder.py", line 258, in buildFinished
	    self.builder.triggerNewBuildCheck()
	  File "/tools/buildbot-schedulerdb//lib/python2.5/site-packages/buildbot/process/builder.py", line 465, in triggerNewBuildCheck
	    self.botmaster.triggerNewBuildCheck()
	  File "/tools/buildbot-schedulerdb//lib/python2.5/site-packages/buildbot/master.py", line 115, in triggerNewBuildCheck
	    self.loop.trigger()
	  File "/tools/buildbot-schedulerdb//lib/python2.5/site-packages/buildbot/loop.py", line 112, in trigger
	    assert self.running
	exceptions.AssertionError: