[GUI request] Parent element

[rk84]

Currently (0.11.x) you can only get parent gui of any gui element with "gui" -key (Parent gui is parent of gui root elements: center, left and top), but getting parent element of an element seems to be missing. This can be bit annoying if path from root to parent element is long. Its even worser if path is unknown, possibly requiring some searching and unique element naming.

My suggestion: Make parent element of gui element readable with "parent" -key.