This reverts commit bdbc739d6e.
Such a change needs more thought put into it. By versioning
shared libraries we'd make a false impression that libraries
themselves are actually versioned and have some sort of stable
ABI, which is not the case.
This will be useful when C bindings become stable, but as long
as they are experimental it does not make sense to set SONAME.
Also this change should not have been backported, since it's
severely breaking.
Compilers in nixpkgs have caught up and major distros
should also have recent enough compilers. It would be
nice to have newer features like more full featured
ranges and deducing this.
