Use codegen engine alternate to Reflection.Emit

[ForNeVeR]

Reflection.Emit is as good start for a codegen engine, but it has its downsides: it requires us to load the assemblies referenced by the generated code in our own process, and not every valid assembly could be represented by Reflection.Emit (because of a sequential nature of its' type generation).

I think, we should use Mono.Cecil instead.