Move the subname utils out into a new Sub::Util package
Add a cautionary note to Sub::Name users, that S:U:subname() is not the same as S:N:subname()
Don't use Test::More 0.88 and done_testing; just supply a test count (for 5.8.x)
Move set_prototype to Sub::Util also, give it a different (nicer) interface; add back-compat proxy from Scalar::Util