THRIFT-531. csharp: C# project and solution files reference external source control system

This patch removes the external source providers from all csproj and sln files. 



git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@790731 13f79535-47bb-0310-9956-ffa450edef68
4 files changed