Add MaxUploadBytes parameter

[benaadams]

Fail fast on Content-Length header value, count for body in chunked when limit passed.

Failure state: current 413 Payload Too Large old 413 Request Entity Too Large

"The request is larger than the server is willing or able to process." RFC7231

.NET 4 - 4.6 default HttpRuntimeSection.MaxRequestLength 4MB
IIS default maxRequestEntityAllowed 200kB
or filtered default 28.6MB (returns 404.13 Content Length Too Large)
ngnix default client_max_body_size 1MB
apache.tomcat default maxPostSize 2MB
apache.httpd default LimitRequestBody unlimited

Will currently be enforced by reverse proxy config (e.g. IIS/nginx) when deployed in recommended configuration - but not in pure Kestrel deployment.

[halter73]

I think we should be careful when implementing this not to limit upgraded/websocket requests.

[muratg]

#475

[muratg]

cc @blowdart

[DamianEdwards]

post-RC2