Merge source code from aspnet/WebSockets

src/WebSockets/.gitignore

src/WebSockets/Directory.Build.props

src/WebSockets/Directory.Build.targets

src/WebSockets/NuGetPackageVerifier.json

src/WebSockets/README.md

src/WebSockets/WebSockets.sln

src/WebSockets/build/Key.snk

src/WebSockets/build/dependencies.props

src/WebSockets/build/repo.props

src/WebSockets/build/repo.targets

src/WebSockets/build/setup-wstest.ps1

src/WebSockets/build/setup-wstest.sh

src/WebSockets/build/sources.props

...obahnTestAppAspNet4/AutobahnTestAppAspNet4.csproj.aspnet4

...WebSockets/samples/AutobahnTestAppAspNet4/EchoSocket.ashx

...Sockets/samples/AutobahnTestAppAspNet4/EchoSocket.ashx.cs

...samples/AutobahnTestAppAspNet4/Properties/AssemblyInfo.cs

...ebSockets/samples/AutobahnTestAppAspNet4/Web.Debug.config

...Sockets/samples/AutobahnTestAppAspNet4/Web.Release.config

src/WebSockets/samples/AutobahnTestAppAspNet4/Web.config