Disable AllowSynchronousIO by default in all servers

[Tratcher]

#4774 #5874
I had to bump IIS's dependencies to get the response compression fix. This will go away when I can rebase on the refs changes.

Let's see how many upstream tests fail...

Blocked by MVC #6397.

[Tratcher]

Rebase on #4962

[Tratcher]

https://github.com/aspnet/AspNetCore/blob/6046ad27f645b1b16cf8253c3ca2b83e27ed2cb3/src/Middleware/CORS/samples/SampleDestination/SampleMiddleware.cs#L28
https://github.com/aspnet/AspNetCore/blob/6046ad27f645b1b16cf8253c3ca2b83e27ed2cb3/src/Middleware/CORS/samples/SampleDestination/Startup.cs#L89

[Tratcher]

Ready for review. The failures are known logging issues @pakrym is dealing with.

[Tratcher]

Hmm, this should have caused more failures, our test code isn't that clean...

I'm going to add the same feature to the test server and see what happens.

[NinoFloris]

What's left of the ambition to expose the pipes instead of sticking with streams?

[Tratcher]

@NinoFloris that's still happening. #4757

[Tratcher]

2018-12-20T00:53:00.2990733Z   Failed   Microsoft.AspNetCore.Server.IISIntegration.FunctionalTests.CompressionModuleTests.DynamicResponsesAreCompressed
2018-12-20T00:53:00.2991617Z   Error Message:
2018-12-20T00:53:00.3000411Z    Assert.Equal() Failure
2018-12-20T00:53:00.3007589Z                                     � (pos 20)
2018-12-20T00:53:00.3007782Z   Expected: Message1\r\nMessage2\r\n
2018-12-20T00:53:00.3012128Z   Actual:   Message1\r\nMessage2\r\n\r\n
2018-12-20T00:53:00.3015538Z                                     � (pos 20)

All other failures look like known unrelated issues.

[davidfowl]

What's left of the ambition to expose the pipes instead of sticking with streams.

There are a bunch of work items for doing this in the 3.0 milestone. We think we have a plan that is both backwards compatible and exposes pipes with streams

[Tratcher]

Blocked by MVC #6397. @davidfowl how about I turn the setting back off by default but merge the other improvements I've made so far like the test fixes, the new test host feature, etc.?

[Tratcher]

Split. #6404 deals with the improvements so far and this PR only deals with changing the defaults.

[davidfowl]

The other thing we can do is turn it off in those code paths to keep everything clean.

[Tratcher]

I doubt that would be clean. Hundreds of MVC tests are affected on many different code paths.

[davidfowl]

I mean no new broken logic would sneak in if we can turn it on globally and enable sync IO on those code paths.

[Tratcher]

Ready for a final review. I've added some fixes and workarounds in MVC, and cleaned up a few more tests elsewhere.

(The Helix failures are unrelated)

[halter73]

Double approved.