Fixes #432

[Kethku]

Fixes #432 by modifying the floating window utility functions to use relative "win" rather than relative "editor". This is because in multigrid environments the position of the documentation window was incorrect as explained in the issue.

[Kethku]

Actually looks like this breaks non multigrid environments... I'll have to think a bit

[Kethku]

I'm not sure what the right solution is. Looks like pum_getpos returns relative positions when multigrid. I could special case whether editor or win is used for the relative property depending on if a gui is connected, but that feels like a hack.

Any guidance would be appreciated

[hrsh7th]

The big change that relates to the documentation window had merged. Could you check the problem with latest compe?

[Kethku]

Finally got around to testing this. Unfortunately its still broken. In a multigrid environment, the documentation window is positioned relative to the top window not the current window

[Kethku]

Changing the relative option in the window creation to win fixes this issue for multigrid environments, but I believe breaks it for normal ones. I'm not sure what the correct way to solves this is for both use cases.