Log Message:
Update to 0.15
--------------
0.15    2015-05-14 20:35 UTC
        + Chg : The new environment variable to enable thread tests on older
                perls is PERL_FORCE_TEST_THREADS. Note that this variable
                should only be turned on by authors.
        + Fix : The module has been taught about the new multideref
                optimization, and will function properly on perl 5.21.11 and
                above.
        + Fix : The module will no longer crash or behave erratically when it
                is loaded by several threads (or Windows emulated processes)
                ran in parallel.
        + Fix : Update the Windows ActivePerl + gcc 3.4 workaround for
                ExtUtils::MakeMaker 7.04. Thanks Christian Walde for reporting
                and feedback on this issue.
        + Fix : Be really compatible with the optional OP_PARENT feature.
        + Tst : $ENV{$Config{ldlibpthname}} is now preserved on all platforms,
                which will address failures of t/43-peep.t and
                t/51-threads-teardown.t with unusual compilers (like icc) that
                link all their compiled objects to their own libraries.