Flag to select -xy to mean -x -y or --x=y (-x y) if x is defined to take params

[xparq]

In case of an "aggregate", -xy z should still mean -x z -y, but it starts to get complicated, e.g. with multiple non-nullary options in the set. So, not a burning priority; spaces have always been there to help... Also, the naturally ordered -yx z already works (as -x z -y).