Add F# syntax

Adds F# syntax to the Standard style, as well as some supporting changes to the framework, and also some minor improvements to the C# syntax in the Standard style. Let me know if you'd like these submitted as separate pull requests, or if you have any other comments about the content or style of the code.

Note that this F# syntax won't cover (anywhere near) all possible syntax. But (with all due respect!) I noticed that neither does the C# syntax, so I'm hoping that's okay, at least to get the ball rolling :-)