[Rd] Useful statusbar in RGui

[talepanda]

This may be Windows specific, so not appropriate for this List...

Currently, when I'm in console of Rgui, the status bar says a simple message
"R majer ver. minor ver. - A Language and Environment" which I know.
When I'm in plot area, it says "R Graphics" which I know, again.


I think it is very useful if statusbars says current directory,
because in my daily use I open several Rgui windows in different
directory (that is, different project), and it is diffecult to find
the window which I want.

Someone may hope something else.


So, my proposal is to allow users to change the message in status bar.

I think that a wrapper for function "setstatus" in
src/guiwin32/graphapp/status.c is enough for this purpose.

thanks