Revert "Fix bug wrt. returning internal SV*"

This reverts commits
43ed7a8c1fcbe36d5dae77a93fa958390f4f1945,
e34c88ec367ccaff1db13b2c1cc6dfa86f0c45ec,
40dc0e8186547b37e5a2754258c857ec14ef12e2,
6d4472948cc41b3966b8f6509dbf472fcdd0b9b3.

Problems with users of the module, see RT #8602 for details.
https://rt.cpan.org/Ticket/Display.html?id=86202
version bump, changelog