WebSharper

WebSharper 4 is currently using two different versions of Mono.Cecil, because one is needed for writing into Roslyn assemblies, but it is way too slow for F# compiled ones. Steps/options: - Resolve issues on cecil-beta branch to test if Mono.Cecil.0.10.0-beta versions have this issue or not - If issue persists on F# speed, try to do a minimal test and report