[nem-en] Typing a expression in context of method

[vc]

> > Maybe pick out RunTyper from constructor and add to RunTyper parameter
> > through which pass expression for typing? And so as to RunTyper return
> TExpr
> > Instead of replacing corresponding MethtBuilder state (convert logic of
> > Typer to functional manner)? At now logic of Typer wery hard to
> understand.
> >
> > Add will be very nice if Typer will get reference to Messenger parameter
> > instead of get it from solver (in Integration we type methods in lazy
> manner
> > and we need intercept messages from typer).
> >
> 
> Good idea.

I tried to make it in last week, but rollback my changes as it too
difficultly for me. :(

Vlad