Doesn't write out byte order mark

[BradBarnich]

Modifying a project removes the BOM. It's not a huge deal, just causes churn. From what I can tell, Visual Studio always writes a BOM to csproj files.

I think the issue is in here: https://github.com/DarthFubuMVC/FubuCsProjFile/blob/master/src/FubuCsProjFile/MSBuild/MSBuildProject.cs#L535

It gets the encoding by name, but to explicitly write out the BOM I think the encoding needs to be constructed this way new UTF8Encoding(true)