Log Message:
Update to version 2.12.

Changes since 2.09:
===================

    Version 2.12
        1. Add regression tests for the auto-require of STORABLE_thaw
        2. Add auto-require of modules to restore overloading (and tests)
        3. Change to no context (should give speedup with ithreads)

    Version 2.11
        1. Storing restricted hashes in canonical order would SEGV. Fixed.
        2. It was impossible to retrieve references to PL_sv_no and and
           PL_sv_undef from STORABLE_thaw hooks.
        3. restrict.t was failing on 5.8.0, due to 5.8.0's unique
           implementation of restricted hashes using PL_sv_undef
        4. These changes allow a space optimisation for restricted hashes.

    Version 2.10
        1. Thread safety: Storable::CLONE/init_perlinterp() now create
           a new Perl context for each new ithread.
           (From Stas Bekman and Jan Dubois.)
        2. Fix a tag count mismatch with $Storable::Deparse that caused
           all back-references after a stored sub to be off-by-N (where
           N was the number of code references in between).
           (From Sam Vilain.)
        3. Prevent CODE references from turning into SCALAR references.
           (From Slaven Rezic.)