Improves Kestrel to reject requests that don't conform to HTTP spec.
RFC 7230 section 5.4: "A server MUST respond with a 400 (Bad Request)
status code to any HTTP/1.1 request message that lacks a Host header
field and to any request message that contains more than one Host
header field or a Host header field with an invalid field-value."
See https://tools.ietf.org/html/rfc7230#section-5.4.
Other changes:
- update VS code settings to work better with CLI 2.0
- update tests that were subject to infinite hangs
Remove runtimeconfig.template.json
Remove ToolsVersion attribute
Use repo.targets instead of makefile.shade
Rename code gen app to shorter name
Use GetOSPlatform task
Upgrade tests to .NET Framework 4.5.2
Cleanup solution configurations. Set the class libraries to AnyCPU even when on the x86 or x64 solution config.