Incorrect window positioning with top taskbar

[Daniel Beardsmore]

When opening certain dialogs such as the XML editor, the window's y-coordinate (including title bar) is set to zero. If the taskbar is at the top of the screen, the title bar ends up behind the taskbar.

I don't know quite what the trigger is, as dialogs sometimes remember where they were left. The XML editor window in 0.91 is the one that consistently fails to remember where it was left, and sadly this is required for simple tasks such as naming grids.

I have a feeling that this window is forgetting to remember its position. (To get to the title bar, simply click the window border and Windows forces it down below the taskbar. It's just very fiddly since the border is so thin now.)

Currently: Inkscape 0.91 64-bit, Windows 10 Pro 64-bit.