* Makeconfig (soversions.i): New target, input-reading parts of

* Makeconfig (soversions.i): New target, input-reading parts of

	soversions.mk generation moved here; result is a canonicalized
	list "LIB VERSION [SET]" for this configuration.
	(soversions.mk): Use that as input.  Don't emit map-firstversions.
	* Makerules (version-renames.def): New target, generated from
	soversions.i with contents that was in $(map-firstversions).
	(Versions.all): Don't depend on soversions.mk, depend on
	version-renames.def instead; just cat it into the input.