Add a "peek" (function preview) capability

When going through code, I'd like to be able to see the code for a function (ala what is done with macros) without opening it in a new pane. Visual Studio added this capability. Source Insight has had it forever.

Source Insight has a neat way to doing it where you can have a window / pane in Qt Creator parlance where you see the info. The nice thing about there scheme is that the info. is always in the same place and the predictability makes it less mentally taxing and more importantly, doesn't visually obscure what you are doing. It also persists for a little bit so that you can have context for what you are doing.

Thank you for considering this.