Shift+Ctrl+P should actually typecheck pieces of code upon which it is invoked

[sxhya]

Current implementation only allows you to see type information that has been dumped and stored during the typechecking process. Due to peculiarities of typechecking this process currently is not 100% reliable (e.g. there is no guarantee that the typechecker will actually infer types for all the subexpressions of a given expression). This also makes Shift+Ctrl+P feature reliant upon the correct operation of autoretypecheck feature.