[Ironruby-core] Littl' question about the build process

[Thibaut Barrère]

> C# 3.0 doesn't require new features from the CLR, just some new libraries (System.Core and friends).

Thanks for the clarification. Then yes, I'll vote for the switch to C#
3.0. Like Jb said, it's a new project, let's move on!