Fixing MassTransit->Quartz integration

[sergeyshaykhullin]

The problem is in ZeroSizeThreadPool and MassTransit way to always-start schedulers

For now i have two solutions:

• Configure MassTransit integration to not to start external schedulers (Somehow(action/strategy, flag, whatever), idea is not complete)
• Ignore scheduler Start/StandBy/Shutdown if ThreadPool is ZeroSizeThreadPool =(

I want to discuss and complete more consistent solution:

• Is not obvious that with ZeroSizeThreadPool Start should not be called
• Is not obvious that with ZeroSizeThreadPool when Start is called nothing happend
• Is not obvious that MassTransit is checking Quartz ThreadPool type and desiding to not to start
• Is not obvious that MassTransit is checking some Quartz flags to deside should it Start scheduler or not (Also is not a good idea to have a lot of flags for whatever it needs. It is complicating configuration)

I think that Quartz has more potential for clean solution than MassTransit.QuartzIntegration, because of available internals

Related:
#1002
#1003
MassTransit/MassTransit#2092

[lahma]

Created to MassTransit/MassTransit#2095 to show one option how to configure this. I don't think there's much to do on Quartz's side.