#38 - Port the Twitter middleware from katana

This is a direct port, no surprises.
Yeah I think in an extremely hypothetical scenario what if you want different defaults in different parts of the app?

But that aside, is setting a static property the right way to configure something like this? Normally we pass things around through DI and various services. Or just tell people to stick it in an `Options` object (which gets plumbed through DI).

@loudej @davidfowl - thoughts on how to plumb things that used to be static?

Of course, maybe this one setting is too trivial to really matter in the grand scheme, but I think the question posed here is still a valid one, even if we choose not to address it here.