Gtk.jl clear canvas on key event

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3

I also realized now you can do the overwrite directly in the keycode function as long as you use reveal() at the end:

    elseif event.keyval == 122
        println(" (z was pressed)")
        ctx = getgc(c)
        set_source_rgb(ctx,1,1,1)
        rectangle(ctx,0,0,600,600)
        fill(ctx)
        reveal(c)
    end