Merge pull request dotnet#4 from henkmollema/fix-readme-links

Updated outdated links

README.md

@@ -14,7 +14,7 @@ ASP.NET.
 
 * [.NET Core Framework](https://github.com/dotnet/corefx)
 * [.NET Core Runtime](https://github.com/dotnet/coreclr)
-* [.NET Compiler Platform ("Roslyn")](https://roslyn.codeplex.com)
+* [.NET Compiler Platform ("Roslyn")](https://github.com/dotnet/roslyn)
 * [ASP.NET 5](https://github.com/aspnet/home)
 
 At present, only a few .NET Core libraries are available on GitHub. The rest of
@@ -25,7 +25,7 @@ the libraries, including the base runtime, will be added in the coming months.
 All projects accept contributions:
 
 * [.NET Core Contributing Guide](https://github.com/dotnet/corefx/wiki/Contributing)
-* [.NET Compiler Platform ("Roslyn")](https://roslyn.codeplex.com/wikipage?title=How%20to%20Contribute&referringTitle=Home)
+* [.NET Compiler Platform ("Roslyn")](https://github.com/dotnet/roslyn/wiki/Contributing-Code)
 * [ASP.NET Contributing Guide](https://github.com/aspnet/Home/blob/master/CONTRIBUTING.md)
 
 You are also encouraged to start a discussion by posting on the
@@ -39,7 +39,7 @@ The .NET Core platform is part of the [.NET Foundation](http://www.dotnetfoundat
 
 * [.NET Core Project](http://www.dotnetfoundation.org/netcore5)
 * [.NET Compiler Platform ("Roslyn" Project)](http://www.dotnetfoundation.org/dotnet-compiler-platform)
-* [ASP.NET Project](http://www.dotnetfoundation.org/aspnet-vnext)
+* [ASP.NET Project](http://www.dotnetfoundation.org/aspnet-5)
 
 ## License
 
@@ -83,4 +83,4 @@ ASP.NET that is designed for the cloud, and runs on Windows, Linux and Mac. It
 uses the .NET Framework to run on Windows, and can also run on .NET Core for
 greater deployment flexibility on Windows. It currently uses Mono for Linux and
 Mac support but will move to .NET Core for those platforms when they are
-supported.
+supported.